<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Concepción-Acevedo, Jeniffer</style></author><author><style face="normal" font="default" size="100%">Miller, Jonathan C</style></author><author><style face="normal" font="default" size="100%">Boucher, Michael J</style></author><author><style face="normal" font="default" size="100%">Klingbeil, Michele M</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Cell cycle localization dynamics of mitochondrial DNA polymerase IC in African trypanosomes.</style></title><secondary-title><style face="normal" font="default" size="100%">Mol Biol Cell</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Mol. Biol. Cell</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Cell Cycle</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA Replication</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA, Kinetoplast</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA-Directed DNA Polymerase</style></keyword><keyword><style  face="normal" font="default" size="100%">Gene Knockdown Techniques</style></keyword><keyword><style  face="normal" font="default" size="100%">Gene Silencing</style></keyword><keyword><style  face="normal" font="default" size="100%">Mitochondria</style></keyword><keyword><style  face="normal" font="default" size="100%">Protozoan Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">S Phase</style></keyword><keyword><style  face="normal" font="default" size="100%">Trypanosoma brucei brucei</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2018</style></year><pub-dates><date><style  face="normal" font="default" size="100%">10/2018</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">29</style></volume><pages><style face="normal" font="default" size="100%">2540-2552</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Trypanosoma brucei has a unique catenated mitochondrial DNA (mtDNA) network called kinetoplast DNA (kDNA). Replication of kDNA occurs once per cell cycle in near synchrony with nuclear S phase and requires the coordination of many proteins. Among these are three essential DNA polymerases (TbPOLIB, IC, and ID). Localization dynamics of these proteins with respect to kDNA replication stages and how they coordinate their functions during replication are not well understood. We previously demonstrated that TbPOLID undergoes dynamic localization changes that are coupled to kDNA replication events. Here, we report the localization of TbPOLIC, a second essential DNA polymerase, and demonstrate the accumulation of TbPOLIC foci at active kDNA replication sites (antipodal sites) during stage II of the kDNA duplication cycle. While TbPOLIC was undetectable by immunofluorescence during other cell cycle stages, steady-state protein levels measured by Western blot remained constant. TbPOLIC foci colocalized with the fraction of TbPOLID that localized to the antipodal sites. However, the partial colocalization of the two essential DNA polymerases suggests a highly dynamic environment at the antipodal sites to coordinate the trafficking of replication proteins during kDNA synthesis. These data indicate that cell cycle-dependent localization is a major regulatory mechanism for essential mtDNA polymerases during kDNA replication.&lt;/p&gt;
</style></abstract><issue><style face="normal" font="default" size="100%">21</style></issue></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Diao, Yuanan</style></author><author><style face="normal" font="default" size="100%">Rodriguez, Victor</style></author><author><style face="normal" font="default" size="100%">Klingbeil, Michele</style></author><author><style face="normal" font="default" size="100%">Arsuaga, Javier</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Orientation of DNA Minicircles Balances Density and Topological Complexity in Kinetoplast DNA.</style></title><secondary-title><style face="normal" font="default" size="100%">PLoS One</style></secondary-title><alt-title><style face="normal" font="default" size="100%">PLoS ONE</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Cell Cycle</style></keyword><keyword><style  face="normal" font="default" size="100%">Crithidia fasciculata</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA Replication</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA, Kinetoplast</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA, Mitochondrial</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2015</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2015</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">10</style></volume><pages><style face="normal" font="default" size="100%">e0130998</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Kinetoplast DNA (kDNA), a unique mitochondrial structure common to trypanosomatid parasites, contains thousands of DNA minicircles that are densely packed and can be topologically linked into a chain mail-like network. Experimental data indicate that every minicircle in the network is, on average, singly linked to three other minicircles (i.e., has mean valence 3) before replication and to six minicircles in the late stages of replication. The biophysical factors that determine the topology of the network and its changes during the cell cycle remain unknown. Using a mathematical modeling approach, we previously showed that volume confinement alone can drive the formation of the network and that it induces a linear relationship between mean valence and minicircle density. Our modeling also predicted a minicircle valence two orders of magnitude greater than that observed in kDNA. To determine the factors that contribute to this discrepancy we systematically analyzed the relationship between the topological properties of the network (i.e., minicircle density and mean valence) and its biophysical properties such as DNA bending, electrostatic repulsion, and minicircle relative position and orientation. Significantly, our results showed that most of the discrepancy between the theoretical and experimental observations can be accounted for by the orientation of the minicircles with volume exclusion due to electrostatic interactions and DNA bending playing smaller roles. Our results are in agreement with the three dimensional kDNA organization model, initially proposed by Delain and Riou, in which minicircles are oriented almost perpendicular to the horizontal plane of the kDNA disk. We suggest that while minicircle confinement drives the formation of kDNA networks, it is minicircle orientation that regulates the topological complexity of the network.&lt;/p&gt;
</style></abstract><issue><style face="normal" font="default" size="100%">6</style></issue></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Benmerzouga, Imaan</style></author><author><style face="normal" font="default" size="100%">Concepción-Acevedo, Jeniffer</style></author><author><style face="normal" font="default" size="100%">Kim, Hee-Sook</style></author><author><style face="normal" font="default" size="100%">Vandoros, Anthula V</style></author><author><style face="normal" font="default" size="100%">Cross, George A M</style></author><author><style face="normal" font="default" size="100%">Klingbeil, Michele M</style></author><author><style face="normal" font="default" size="100%">Li, Bibo</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Trypanosoma brucei Orc1 is essential for nuclear DNA replication and affects both VSG silencing and VSG switching.</style></title><secondary-title><style face="normal" font="default" size="100%">Mol Microbiol</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Mol. Microbiol.</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Antigenic Variation</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA Replication</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA, Protozoan</style></keyword><keyword><style  face="normal" font="default" size="100%">Gene Silencing</style></keyword><keyword><style  face="normal" font="default" size="100%">Genes, Protozoan</style></keyword><keyword><style  face="normal" font="default" size="100%">Membrane Glycoproteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Origin Recognition Complex</style></keyword><keyword><style  face="normal" font="default" size="100%">Promoter Regions, Genetic</style></keyword><keyword><style  face="normal" font="default" size="100%">Trypanosoma brucei brucei</style></keyword><keyword><style  face="normal" font="default" size="100%">Variant Surface Glycoproteins, Trypanosoma</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2013</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2013 Jan</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">87</style></volume><pages><style face="normal" font="default" size="100%">196-210</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Binding of the Origin Recognition Complex (ORC) to replication origins is essential for initiation of DNA replication, but ORC has non-essential functions outside of DNA replication, including in heterochromatic gene silencing and telomere maintenance. Trypanosoma brucei, a protozoan parasite that causes human African trypanosomiasis, uses antigenic variation as a major virulence mechanism to evade the host&amp;#39;s immune attack by expressing its major surface antigen, the Variant Surface Glycoprotein (VSG), in a monoallelic manner. An Orc1/Cdc6 homologue has been identified in T.&amp;thinsp;brucei, but its role in DNA replication has not been directly confirmed and its potential involvement in VSG repression or switching has not been thoroughly investigated. In this study, we show that TbOrc1 is essential for nuclear DNA replication in mammalian-infectious bloodstream and tsetse procyclic forms (BF and PF). Depletion of TbOrc1 resulted in derepression of telomere-linked silent VSGs in both BF and PF, and increased VSG switching particularly through the in situ transcriptional switching mechanism. TbOrc1 associates with telomere repeats but appears to do so independently of two known T.&amp;thinsp;brucei telomere proteins, TbRAP1 and TbTRF. We conclude that TbOrc1 has conserved functions in DNA replication and is also required to control telomere-linked VSG expression and VSG switching.&lt;/p&gt;
</style></abstract><issue><style face="normal" font="default" size="100%">1</style></issue></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Marceau, Aimee H</style></author><author><style face="normal" font="default" size="100%">Bahng, Soon</style></author><author><style face="normal" font="default" size="100%">Massoni, Shawn C</style></author><author><style face="normal" font="default" size="100%">George, Nicholas P</style></author><author><style face="normal" font="default" size="100%">Sandler, Steven J</style></author><author><style face="normal" font="default" size="100%">Marians, Kenneth J</style></author><author><style face="normal" font="default" size="100%">Keck, James L</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Structure of the SSB-DNA polymerase III interface and its role in DNA replication.</style></title><secondary-title><style face="normal" font="default" size="100%">EMBO J</style></secondary-title><alt-title><style face="normal" font="default" size="100%">EMBO J.</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Amino Acid Sequence</style></keyword><keyword><style  face="normal" font="default" size="100%">Bacterial Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Base Sequence</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA Polymerase III</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA Replication</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA, Single-Stranded</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA-Binding Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Escherichia coli</style></keyword><keyword><style  face="normal" font="default" size="100%">Escherichia coli Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Holoenzymes</style></keyword><keyword><style  face="normal" font="default" size="100%">Molecular Sequence Data</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2011</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2011 Oct 19</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">30</style></volume><pages><style face="normal" font="default" size="100%">4236-47</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Interactions between single-stranded DNA-binding proteins (SSBs) and the DNA replication machinery are found in all organisms, but the roles of these contacts remain poorly defined. In Escherichia coli, SSB's association with the χ subunit of the DNA polymerase III holoenzyme has been proposed to confer stability to the replisome and to aid delivery of primers to the lagging-strand DNA polymerase. Here, the SSB-binding site on χ is identified crystallographically and biochemical and cellular studies delineate the consequences of destabilizing the χ/SSB interface. An essential role for the χ/SSB interaction in lagging-strand primer utilization is not supported. However, sequence changes in χ that block complex formation with SSB lead to salt-dependent uncoupling of leading- and lagging-strand DNA synthesis and to a surprising obstruction of the leading-strand DNA polymerase in vitro, pointing to roles for the χ/SSB complex in replisome establishment and maintenance. Destabilization of the χ/SSB complex in vivo produces cells with temperature-dependent cell cycle defects that appear to arise from replisome instability.</style></abstract><issue><style face="normal" font="default" size="100%">20</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/21857649?dopt=Abstract</style></custom1></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Bruhn, David F</style></author><author><style face="normal" font="default" size="100%">Sammartino, Mark P</style></author><author><style face="normal" font="default" size="100%">Klingbeil, Michele M</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Three mitochondrial DNA polymerases are essential for kinetoplast DNA replication and survival of bloodstream form Trypanosoma brucei.</style></title><secondary-title><style face="normal" font="default" size="100%">Eukaryot Cell</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Eukaryotic Cell</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Cell Survival</style></keyword><keyword><style  face="normal" font="default" size="100%">Cells, Cultured</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA Replication</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA, Kinetoplast</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA-Directed DNA Polymerase</style></keyword><keyword><style  face="normal" font="default" size="100%">Humans</style></keyword><keyword><style  face="normal" font="default" size="100%">Membrane Potential, Mitochondrial</style></keyword><keyword><style  face="normal" font="default" size="100%">Mitochondria</style></keyword><keyword><style  face="normal" font="default" size="100%">Parasitemia</style></keyword><keyword><style  face="normal" font="default" size="100%">RNA Interference</style></keyword><keyword><style  face="normal" font="default" size="100%">Trypanosoma brucei brucei</style></keyword><keyword><style  face="normal" font="default" size="100%">Trypanosomiasis, African</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2011</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2011 Jun</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">10</style></volume><pages><style face="normal" font="default" size="100%">734-43</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Trypanosoma brucei, the causative agent of human African trypanosomiasis, has a complex life cycle that includes multiple life cycle stages and metabolic changes as the parasite switches between insect vector and mammalian host. The parasite's single mitochondrion contains a unique catenated mitochondrial DNA network called kinetoplast DNA (kDNA) that is composed of minicircles and maxicircles. Long-standing uncertainty about the requirement of kDNA in bloodstream form (BF) T. brucei has recently eroded, with reports of posttranscriptional editing and subsequent translation of kDNA-encoded transcripts as essential processes for BF parasites. These studies suggest that kDNA and its faithful replication are indispensable for this life cycle stage. Here we demonstrate that three kDNA replication proteins (mitochondrial DNA polymerases IB, IC, and ID) are required for BF parasite viability. Silencing of each polymerase was lethal, resulting in kDNA loss, persistence of prereplication DNA monomers, and collapse of the mitochondrial membrane potential. These data demonstrate that kDNA replication is indeed crucial for BF T. brucei. The contributions of mitochondrial DNA polymerases IB, IC, and ID to BF parasite viability suggest that these and other kDNA replication proteins warrant further investigation as a new class of targets for the development of antitrypanosomal drugs.</style></abstract><issue><style face="normal" font="default" size="100%">6</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/21531873?dopt=Abstract</style></custom1></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Bruhn, David F</style></author><author><style face="normal" font="default" size="100%">Mozeleski, Brian</style></author><author><style face="normal" font="default" size="100%">Falkin, Laurie</style></author><author><style face="normal" font="default" size="100%">Klingbeil, Michele M</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Mitochondrial DNA polymerase POLIB is essential for minicircle DNA replication in African trypanosomes.</style></title><secondary-title><style face="normal" font="default" size="100%">Mol Microbiol</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Mol. Microbiol.</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">DNA Polymerase beta</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA Replication</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA, Kinetoplast</style></keyword><keyword><style  face="normal" font="default" size="100%">Gene Silencing</style></keyword><keyword><style  face="normal" font="default" size="100%">Protozoan Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Trypanosoma brucei brucei</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2010</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2010 Mar</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">75</style></volume><pages><style face="normal" font="default" size="100%">1414-25</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The unique mitochondrial DNA of trypanosomes is a catenated network of minicircles and maxicircles called kinetoplast DNA (kDNA). The network is essential for survival, and requires an elaborate topoisomerase-mediated release and reattachment mechanism for minicircle theta structure replication. At least seven DNA polymerases (pols) are involved in kDNA transactions, including three essential proteins related to bacterial DNA pol I (POLIB, POLIC and POLID). How Trypanosoma brucei utilizes multiple DNA pols to complete the topologically complex task of kDNA replication is unknown. To fill this gap in knowledge we investigated the cellular role of POLIB using RNA interference (RNAi). POLIB silencing resulted in growth inhibition and progressive loss of kDNA networks. Additionally, unreplicated covalently closed precursors become the most abundant minicircle replication intermediate as minicircle copy number declines. Leading and lagging strand minicircle progeny similarly declined during POLIB silencing, indicating POLIB had no apparent strand preference. Interestingly, POLIB RNAi led to the accumulation of a novel population of free minicircles that is composed mainly of covalently closed minicircle dimers. Based on these data, we propose that POLIB performs an essential role at the core of the minicircle replication machinery.</style></abstract><issue><style face="normal" font="default" size="100%">6</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/20132449?dopt=Abstract</style></custom1></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Long, Jarukit Edward</style></author><author><style face="normal" font="default" size="100%">Massoni, Shawn C</style></author><author><style face="normal" font="default" size="100%">Sandler, Steven J</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">RecA4142 causes SOS constitutive expression by loading onto reversed replication forks in Escherichia coli K-12.</style></title><secondary-title><style face="normal" font="default" size="100%">J Bacteriol</style></secondary-title><alt-title><style face="normal" font="default" size="100%">J. Bacteriol.</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Bacterial Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Deoxyribonucleases</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA Helicases</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA Replication</style></keyword><keyword><style  face="normal" font="default" size="100%">Endodeoxyribonucleases</style></keyword><keyword><style  face="normal" font="default" size="100%">Escherichia coli K12</style></keyword><keyword><style  face="normal" font="default" size="100%">Escherichia coli Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Exodeoxyribonuclease V</style></keyword><keyword><style  face="normal" font="default" size="100%">Exodeoxyribonucleases</style></keyword><keyword><style  face="normal" font="default" size="100%">Exonucleases</style></keyword><keyword><style  face="normal" font="default" size="100%">Microscopy, Fluorescence</style></keyword><keyword><style  face="normal" font="default" size="100%">Mutation</style></keyword><keyword><style  face="normal" font="default" size="100%">Rec A Recombinases</style></keyword><keyword><style  face="normal" font="default" size="100%">SOS Response (Genetics)</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2010</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2010 May</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">192</style></volume><pages><style face="normal" font="default" size="100%">2575-82</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Escherichia coli initiates the SOS response when single-stranded DNA (ssDNA) produced by DNA damage is bound by RecA and forms a RecA-DNA filament. recA SOS constitutive [recA(Con)] mutants induce the SOS response in the absence of DNA damage. It has been proposed that recA(Con) mutants bind to ssDNA at replication forks, although the specific mechanism is unknown. Previously, it had been shown that recA4142(F217Y), a novel recA(Con) mutant, was dependent on RecBCD for its high SOS constitutive [SOS(Con)] expression. This was presumably because RecA4142 was loaded at a double-strand end (DSE) of DNA. Herein, it is shown that recA4142 SOS(Con) expression is additionally dependent on ruvAB (replication fork reversal [RFR] activity only) and recJ (5'--&gt;3' exonuclease), xonA (3'--&gt;5' exonuclease) and partially dependent on recQ (helicase). Lastly, sbcCD mutations (Mre11/Rad50 homolog) in recA4142 strains caused full SOS(Con) expression in an ruvAB-, recBCD-, recJ-, and xonA-independent manner. It is hypothesized that RuvAB catalyzes RFR, RecJ and XonA blunt the DSE (created by the RFR), and then RecBCD loads RecA4142 onto this end to produce SOS(Con) expression. In sbcCD mutants, RecA4142 can bind other DNA substrates by itself that are normally degraded by the SbcCD nuclease.</style></abstract><issue><style face="normal" font="default" size="100%">10</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/20304994?dopt=Abstract</style></custom1></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Klingbeil, Michele M</style></author><author><style face="normal" font="default" size="100%">Shapiro, Theresa A</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Unraveling the secrets of regulating mitochondrial DNA replication.</style></title><secondary-title><style face="normal" font="default" size="100%">Mol Cell</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Mol. Cell</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Animals</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA Helicases</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA Replication</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA, Kinetoplast</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA, Mitochondrial</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA, Protozoan</style></keyword><keyword><style  face="normal" font="default" size="100%">Gene Expression Regulation</style></keyword><keyword><style  face="normal" font="default" size="100%">Mutation</style></keyword><keyword><style  face="normal" font="default" size="100%">Peptide Hydrolases</style></keyword><keyword><style  face="normal" font="default" size="100%">Protozoan Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Time Factors</style></keyword><keyword><style  face="normal" font="default" size="100%">Trypanosoma brucei brucei</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2009</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2009 Aug 28</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">35</style></volume><pages><style face="normal" font="default" size="100%">398-400</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">In this issue, Liu et al. (2009) report that maxicircle DNA copy number in trypanosomes is regulated by proteolysis of a helicase; the complex kinetoplast DNA system yields a clear view of how mitochondrial DNA replication can be regulated.</style></abstract><issue><style face="normal" font="default" size="100%">4</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/19716784?dopt=Abstract</style></custom1></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Chandler, Julian</style></author><author><style face="normal" font="default" size="100%">Vandoros, Anthula V</style></author><author><style face="normal" font="default" size="100%">Mozeleski, Brian</style></author><author><style face="normal" font="default" size="100%">Klingbeil, Michele M</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Stem-loop silencing reveals that a third mitochondrial DNA polymerase, POLID, is required for kinetoplast DNA replication in trypanosomes.</style></title><secondary-title><style face="normal" font="default" size="100%">Eukaryot Cell</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Eukaryotic Cell</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Animals</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA Replication</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA, Kinetoplast</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA-Directed DNA Polymerase</style></keyword><keyword><style  face="normal" font="default" size="100%">Mitochondria</style></keyword><keyword><style  face="normal" font="default" size="100%">Mitochondrial Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Protozoan Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">RNA Interference</style></keyword><keyword><style  face="normal" font="default" size="100%">RNA, Double-Stranded</style></keyword><keyword><style  face="normal" font="default" size="100%">Trypanosoma brucei brucei</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2008</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2008 Dec</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">7</style></volume><pages><style face="normal" font="default" size="100%">2141-6</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Kinetoplast DNA (kDNA), the mitochondrial genome of trypanosomes, is a catenated network containing thousands of minicircles and tens of maxicircles. The topological complexity dictates some unusual features including a topoisomerase-mediated release-and-reattachment mechanism for minicircle replication and at least six mitochondrial DNA polymerases (Pols) for kDNA transactions. Previously, we identified four family A DNA Pols from Trypanosoma brucei with similarity to bacterial DNA Pol I and demonstrated that two (POLIB and POLIC) were essential for maintaining the kDNA network, while POLIA was not. Here, we used RNA interference to investigate the function of POLID in procyclic T. brucei. Stem-loop silencing of POLID resulted in growth arrest and the progressive loss of the kDNA network. Additional defects in kDNA replication included a rapid decline in minicircle and maxicircle abundance and a transient accumulation of minicircle replication intermediates before loss of the kDNA network. These results demonstrate that POLID is a third essential DNA Pol required for kDNA replication. While other eukaryotes utilize a single DNA Pol (Pol gamma) for replication of mitochondrial DNA, T. brucei requires at least three to maintain the complex kDNA network.</style></abstract><issue><style face="normal" font="default" size="100%">12</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/18849470?dopt=Abstract</style></custom1></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Lopper, Matthew</style></author><author><style face="normal" font="default" size="100%">Boonsombat, Ruethairat</style></author><author><style face="normal" font="default" size="100%">Sandler, Steven J</style></author><author><style face="normal" font="default" size="100%">Keck, James L</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">A hand-off mechanism for primosome assembly in replication restart.</style></title><secondary-title><style face="normal" font="default" size="100%">Mol Cell</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Mol. Cell</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Binding Sites</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA Helicases</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA Replication</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA, Bacterial</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA, Single-Stranded</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA-Binding Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA-Directed DNA Polymerase</style></keyword><keyword><style  face="normal" font="default" size="100%">Escherichia coli</style></keyword><keyword><style  face="normal" font="default" size="100%">Escherichia coli Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Genome, Bacterial</style></keyword><keyword><style  face="normal" font="default" size="100%">Models, Biological</style></keyword><keyword><style  face="normal" font="default" size="100%">Multienzyme Complexes</style></keyword><keyword><style  face="normal" font="default" size="100%">Protein Binding</style></keyword><keyword><style  face="normal" font="default" size="100%">Replication Origin</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2007</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2007 Jun 22</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">26</style></volume><pages><style face="normal" font="default" size="100%">781-93</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Collapsed DNA replication forks must be reactivated through origin-independent reloading of the replication machinery (replisome) to ensure complete duplication of cellular genomes. In E. coli, the PriA-dependent pathway is the major replication restart mechanism and requires primosome proteins PriA, PriB, and DnaT for replisome reloading. However, the molecular mechanisms that regulate origin-independent replisome loading are not fully understood. Here, we demonstrate that assembly of primosome protein complexes represents a key regulatory mechanism, as inherently weak PriA-PriB and PriB-DnaT interactions are strongly stimulated by single-stranded DNA. Furthermore, the binding site on PriB for single-stranded DNA partially overlaps the binding sites for PriA and DnaT, suggesting a dynamic primosome assembly process in which single-stranded DNA is handed off from one primosome protein to another as a repaired replication fork is reactivated. This model helps explain how origin-independent initiation of DNA replication is restricted to repaired replication forks, preventing overreplication of the genome.</style></abstract><issue><style face="normal" font="default" size="100%">6</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/17588514?dopt=Abstract</style></custom1></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Boonsombat, Ruethairat</style></author><author><style face="normal" font="default" size="100%">Yeh, Su-Ping</style></author><author><style face="normal" font="default" size="100%">Milne, Amy</style></author><author><style face="normal" font="default" size="100%">Sandler, Steven J</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">A novel dnaC mutation that suppresses priB rep mutant phenotypes in Escherichia coli K-12.</style></title><secondary-title><style face="normal" font="default" size="100%">Mol Microbiol</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Mol. Microbiol.</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">DNA Replication</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA-Binding Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Escherichia coli</style></keyword><keyword><style  face="normal" font="default" size="100%">Escherichia coli Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Genes, Dominant</style></keyword><keyword><style  face="normal" font="default" size="100%">Genes, Lethal</style></keyword><keyword><style  face="normal" font="default" size="100%">Genes, Recessive</style></keyword><keyword><style  face="normal" font="default" size="100%">Mutant Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Mutation</style></keyword><keyword><style  face="normal" font="default" size="100%">Phenotype</style></keyword><keyword><style  face="normal" font="default" size="100%">Suppression, Genetic</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2006</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2006 May</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">60</style></volume><pages><style face="normal" font="default" size="100%">973-83</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The loading of a replisome in prokaryotic and eukaryotic cells at an origin of DNA replication and during replication restart is a highly ordered and regulated process. During replication restart in Escherichia coli, the PriA, PriB, PriC, DnaT and Rep proteins form multiple pathways that bind to repaired replication forks. These complexes are then recognized by DnaC as sites to load DnaB, the replicative helicase. Several dnaC mutations have been isolated that suppress phenotypes of some replication restart mutants. A new dnaC mutation (dnaC824) is reported here that efficiently suppresses priB rep mutant phenotypes. Furthermore, it is shown that dnaC824 will suppress phenotypes of priB priA300, rep priA300 and priB priC strains. Unlike other dnaC suppressors, it can only weakly suppress the absence of priA. Others have reported a different type of dnaC mutation, dnaC1331, is able to mimic priB mutant phenotypes. This is supported herein by showing that like dnaC1331, a priB mutation is synthetically lethal with a dam mutation and this can be rescued by a mutH mutation. Furthermore, priB dam lethality can also be suppressed by dnaC824. Like a priB mutation, a dnaC1331 mutation causes a priA2::kan-like phenotype when combined with priA300. Lastly, we show that dnaC824 is dominant to wild type and that dnaC1331 is recessive to wild type. Several models are discussed for the action of these mutant dnaC proteins in replication restart.</style></abstract><issue><style face="normal" font="default" size="100%">4</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/16677308?dopt=Abstract</style></custom1></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Renzette, Nicholas</style></author><author><style face="normal" font="default" size="100%">Gumlaw, Nathan</style></author><author><style face="normal" font="default" size="100%">Nordman, Jared T</style></author><author><style face="normal" font="default" size="100%">Krieger, Marlee</style></author><author><style face="normal" font="default" size="100%">Yeh, Su-Ping</style></author><author><style face="normal" font="default" size="100%">Long, Edward</style></author><author><style face="normal" font="default" size="100%">Centore, Richard</style></author><author><style face="normal" font="default" size="100%">Boonsombat, Ruethairat</style></author><author><style face="normal" font="default" size="100%">Sandler, Steven J</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Localization of RecA in Escherichia coli K-12 using RecA-GFP.</style></title><secondary-title><style face="normal" font="default" size="100%">Mol Microbiol</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Mol. Microbiol.</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Chromosomes, Bacterial</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA Replication</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA, Bacterial</style></keyword><keyword><style  face="normal" font="default" size="100%">Escherichia coli</style></keyword><keyword><style  face="normal" font="default" size="100%">Escherichia coli Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Green Fluorescent Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Mutation</style></keyword><keyword><style  face="normal" font="default" size="100%">Rec A Recombinases</style></keyword><keyword><style  face="normal" font="default" size="100%">Recombinant Fusion Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Recombination, Genetic</style></keyword><keyword><style  face="normal" font="default" size="100%">Ultraviolet Rays</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2005</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2005 Aug</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">57</style></volume><pages><style face="normal" font="default" size="100%">1074-85</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">RecA is important in recombination, DNA repair and repair of replication forks. It functions through the production of a protein-DNA filament. To study the localization of RecA in live Escherichia coli cells, the RecA protein was fused to the green fluorescence protein (GFP). Strains with this gene have recombination/DNA repair activities three- to tenfold below wild type (or about 1000-fold above that of a recA null mutant). RecA-GFP cells have a background of green fluorescence punctuated with up to five foci per cell. Two types of foci have been defined: 4,6-diamidino-2-phenylindole (DAPI)-sensitive foci that are bound to DNA and DAPI-insensitive foci that are DNA-less aggregates/storage structures. In log phase cells, foci were not localized to any particular region. After UV irradiation, the number of foci increased and they localized to the cell centre. This suggested colocalization with the DNA replication factory. recA, recB and recF strains showed phenotypes and distributions of foci consistent with the predicted effects of these mutations.</style></abstract><issue><style face="normal" font="default" size="100%">4</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/16091045?dopt=Abstract</style></custom1></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Sandler, Steven J</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Requirements for replication restart proteins during constitutive stable DNA replication in Escherichia coli K-12.</style></title><secondary-title><style face="normal" font="default" size="100%">Genetics</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Genetics</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Bacterial Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA Replication</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA, Bacterial</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA-Binding Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Escherichia coli</style></keyword><keyword><style  face="normal" font="default" size="100%">Escherichia coli Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Gene Expression Regulation, Bacterial</style></keyword><keyword><style  face="normal" font="default" size="100%">Genome, Bacterial</style></keyword><keyword><style  face="normal" font="default" size="100%">Macromolecular Substances</style></keyword><keyword><style  face="normal" font="default" size="100%">Models, Genetic</style></keyword><keyword><style  face="normal" font="default" size="100%">Mutation</style></keyword><keyword><style  face="normal" font="default" size="100%">Mutation, Missense</style></keyword><keyword><style  face="normal" font="default" size="100%">Phenotype</style></keyword><keyword><style  face="normal" font="default" size="100%">Rec A Recombinases</style></keyword><keyword><style  face="normal" font="default" size="100%">RNA</style></keyword><keyword><style  face="normal" font="default" size="100%">SOS Response (Genetics)</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2005</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2005 Apr</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">169</style></volume><pages><style face="normal" font="default" size="100%">1799-806</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Constitutive stable DNA replication (cSDR) is a mechanism for replisome loading in Escherichia coli K-12. This occurs in a dnaA-independent fashion in an rnhA mutant. cSDR is dependent on recA, priA, and transcription. In this report, it is shown that dnaA rnhA mutants using cSDR for initiation of their DNA replication additionally require priB, but not priC, for viability. Two subtle priA missense mutations either eliminated the ability to grow using cSDR (priA301 C479Y) or resulted in very small colonies (priA300 K230R). DnaC809, a priA suppressor, failed to allow priA or priB mutants to grow using cSDR to initiate DNA replication. Furthermore, unlike dnaC(+) strains, dnaC809 strains require priC for cSDR. DnaC809,820, a priC-independent suppressor of priA2::kan phenotypes, allowed priA and priC (but not priB) mutants to grow using cSDR to initiate DNA replication. It is also shown that rep and rnhA mutations are synthetically lethal. DnaC809 and dnaC809,820 mutations suppress this lethality. Rep is further shown to be required for cSDR in a dnaC809 strain. A model whereby these different sets of replication restart proteins interact preferentially with substrates associated with either RecA or SSB during replication restart and cSDR, respectively, is proposed.</style></abstract><issue><style face="normal" font="default" size="100%">4</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/15716497?dopt=Abstract</style></custom1></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Hinds, Tania</style></author><author><style face="normal" font="default" size="100%">Sandler, Steven J</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Allele specific synthetic lethality between priC and dnaAts alleles at the permissive temperature of 30 degrees C in E. coli K-12.</style></title><secondary-title><style face="normal" font="default" size="100%">BMC Microbiol</style></secondary-title><alt-title><style face="normal" font="default" size="100%">BMC Microbiol.</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Alleles</style></keyword><keyword><style  face="normal" font="default" size="100%">Bacterial Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA Replication</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA-Binding Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Escherichia coli K12</style></keyword><keyword><style  face="normal" font="default" size="100%">Escherichia coli Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Gene Expression Regulation, Bacterial</style></keyword><keyword><style  face="normal" font="default" size="100%">Genes, Lethal</style></keyword><keyword><style  face="normal" font="default" size="100%">Mutation</style></keyword><keyword><style  face="normal" font="default" size="100%">Temperature</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2004</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2004</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">4</style></volume><pages><style face="normal" font="default" size="100%">47</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">BACKGROUND: DnaA is an essential protein in the regulation and initiation of DNA replication in many bacteria. It forms a protein-DNA complex at oriC to which DnaC loads DnaB. DNA replication forks initiated at oriC by DnaA can collapse on route to the terminus for a variety of reasons. PriA, PriB, PriC, DnaT, Rep and DnaC form multiple pathways to restart repaired replication forks. DnaC809 and dnaC809,820 are suppressors of priA2::kan mutant phenotypes. The former requires PriC and Rep while the latter is independent of them. RnhA339::cat mutations allow DnaA-independent initiation of DNA replication.

RESULTS: It is shown herein that a priC303::kan mutation is synthetically lethal with either a dnaA46 or dnaA508 temperature sensitive mutation at the permissive temperature of 30 degrees C. The priC-dnaA lethality is specific for the dnaA allele. The priC303::kan mutant was viable when placed in combination with either dnaA5, dnaA167, dnaA204 or dnaA602. The priC-dnaA508 and priC-dnaA46 lethality could be suppressed by rnhA339::cat. The priC-dnaA508 lethality could be suppressed by a dnaC809,820 mutation, but not dnaC809. Neither of the dnaC mutations could suppress the priC-dnaA46 lethality.

CONCLUSIONS: A hitherto unknown function for either DnaA in replication restart or PriC in initiation of DNA replication that occurs in certain dnaA temperature sensitive mutant strains at the permissive temperature of 30 degrees C has been documented. Models considering roles for PriC during initiation of DNA replication and roles for DnaA in replication restart were tested and found not to decisively explain the data. Other roles of dnaA in transcription and nucleoid structure are additionally considered.</style></abstract><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/15588282?dopt=Abstract</style></custom1></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Klingbeil, Michele M</style></author><author><style face="normal" font="default" size="100%">Englund, Paul T</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Closing the gaps in kinetoplast DNA network replication.</style></title><secondary-title><style face="normal" font="default" size="100%">Proc Natl Acad Sci U S A</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Proc. Natl. Acad. Sci. U.S.A.</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Animals</style></keyword><keyword><style  face="normal" font="default" size="100%">Crithidia fasciculata</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA Ligases</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA Replication</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA, Kinetoplast</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA, Mitochondrial</style></keyword><keyword><style  face="normal" font="default" size="100%">Microscopy, Electron</style></keyword><keyword><style  face="normal" font="default" size="100%">Trypanosoma brucei brucei</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2004</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2004 Mar 30</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">101</style></volume><pages><style face="normal" font="default" size="100%">4333-4</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><issue><style face="normal" font="default" size="100%">13</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/15070715?dopt=Abstract</style></custom1></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">McCool, Jesse D</style></author><author><style face="normal" font="default" size="100%">Ford, Christopher C</style></author><author><style face="normal" font="default" size="100%">Sandler, Steven J</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">A dnaT mutant with phenotypes similar to those of a priA2::kan mutant in Escherichia coli K-12.</style></title><secondary-title><style face="normal" font="default" size="100%">Genetics</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Genetics</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Base Sequence</style></keyword><keyword><style  face="normal" font="default" size="100%">Codon</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA Primers</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA Repair</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA Replication</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA, Bacterial</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA-Binding Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Escherichia coli K12</style></keyword><keyword><style  face="normal" font="default" size="100%">Escherichia coli Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Molecular Sequence Data</style></keyword><keyword><style  face="normal" font="default" size="100%">Mutation</style></keyword><keyword><style  face="normal" font="default" size="100%">Plasmids</style></keyword><keyword><style  face="normal" font="default" size="100%">Polymerase Chain Reaction</style></keyword><keyword><style  face="normal" font="default" size="100%">Sequence Deletion</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2004</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2004 Jun</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">167</style></volume><pages><style face="normal" font="default" size="100%">569-78</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The ability to repair damaged replication forks and restart them is important for cell survival. DnaT is essential for replication restart in vitro and yet no definite genetic analysis has been done in Escherichia coli K-12. To begin, dnaT822, an in-frame six-codon (87-92) deletion was constructed. DnaT822 mutants show colony size, cell morphology, inability to properly partition nucleoids, UV sensitivity, and basal SOS expression similar to priA2::kan mutants. DnaT822 priA2::kan double mutants had phenotypes similar to those of the single mutants. DnaT822 and dnaT822 priA2::kan mutant phenotypes were fully suppressed by dnaC809. Previously, a dominant temperature-sensitive lethal mutation, dnaT1, had been isolated in E. coli 15T(-). DnaT1 was found to have a base-pair change relative to the E. coli 15T(-) and E. coli K-12 dnaT genes that led to a single amino acid change: R152C. A plasmid-encoded E. coli K-12 mutant dnaT gene with the R152C amino acid substitution did not display a dominant temperature-sensitive lethal phenotype in a dnaT(+) strain of E. coli K-12. Instead, this mutant dnaT gene was found to complement the E. coli K-12 dnaT822 mutant phenotypes. The significance of these results is discussed in terms of models for replication restart.</style></abstract><issue><style face="normal" font="default" size="100%">2</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/15238512?dopt=Abstract</style></custom1></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Sandler, S J</style></author><author><style face="normal" font="default" size="100%">McCool, J D</style></author><author><style face="normal" font="default" size="100%">Do, T T</style></author><author><style face="normal" font="default" size="100%">Johansen, R U</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">PriA mutations that affect PriA-PriC function during replication restart.</style></title><secondary-title><style face="normal" font="default" size="100%">Mol Microbiol</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Mol. Microbiol.</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Bacterial Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Bacteriophage mu</style></keyword><keyword><style  face="normal" font="default" size="100%">Cell Division</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA Replication</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA-Binding Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Escherichia coli</style></keyword><keyword><style  face="normal" font="default" size="100%">Escherichia coli Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Genes, Lethal</style></keyword><keyword><style  face="normal" font="default" size="100%">Genotype</style></keyword><keyword><style  face="normal" font="default" size="100%">Models, Biological</style></keyword><keyword><style  face="normal" font="default" size="100%">Mutation, Missense</style></keyword><keyword><style  face="normal" font="default" size="100%">Phenotype</style></keyword><keyword><style  face="normal" font="default" size="100%">Replication Protein A</style></keyword><keyword><style  face="normal" font="default" size="100%">SOS Response (Genetics)</style></keyword><keyword><style  face="normal" font="default" size="100%">Ultraviolet Rays</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2001</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2001 Aug</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">41</style></volume><pages><style face="normal" font="default" size="100%">697-704</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">In Escherichia coli, repair and restart of collapsed replication forks is thought to be essential for cell growth. The replication restart proteins, PriA, PriB, PriC, DnaB, DnaC, DnaG, DnaT and Rep, form redundant pathways that recognize repaired replication forks and restart them. Recognition, modulation of specific DNA structures and loading of the replicative helicase by the replication restart proteins, is likely to be important for replication restart. It has been hypothesized that PriB and PriC function with PriA in genetically separate and redundant PriA-PriB and PriA-PriC pathways. In this study, the del(priB)302 or priC303:kan mutations were used to isolate the PriA-PriB and PriA-PriC pathways genetically so that the effects of three priA missense mutations, priA300 (K230R), priA301 (C479Y) and priA306 (L557P), on these pathways could be assessed. In a wild-type background, the three priA mutations had little, if any, effect on the phenotypes of UV resistance, basal levels of SOS expression and cell viability. In the priB mutant, priA300 and priA301 caused dramatic negative changes in the three phenotypes listed above (and others), whereas the third priA mutant allele, priA306, showed very little negative effect. In the priC mutant, all three priA mutations behaved similarly, producing little, if any, changes in phenotypes. We conclude that priA300 and priA301 mostly affect the PriA-PriC pathway and do so more than priA306. We suggest that PriA's helicase activity is important for the PriA-PriC pathway of replication restart.</style></abstract><issue><style face="normal" font="default" size="100%">3</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/11532137?dopt=Abstract</style></custom1></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Morris, J C</style></author><author><style face="normal" font="default" size="100%">Drew, M E</style></author><author><style face="normal" font="default" size="100%">Klingbeil, M M</style></author><author><style face="normal" font="default" size="100%">Motyka, S A</style></author><author><style face="normal" font="default" size="100%">Saxowsky, T T</style></author><author><style face="normal" font="default" size="100%">Wang, Z</style></author><author><style face="normal" font="default" size="100%">Englund, P T</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Replication of kinetoplast DNA: an update for the new millennium.</style></title><secondary-title><style face="normal" font="default" size="100%">Int J Parasitol</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Int. J. Parasitol.</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Animals</style></keyword><keyword><style  face="normal" font="default" size="100%">Crithidia fasciculata</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA Replication</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA, Kinetoplast</style></keyword><keyword><style  face="normal" font="default" size="100%">Forecasting</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2001</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2001 May 1</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">31</style></volume><pages><style face="normal" font="default" size="100%">453-8</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">In this review we will describe the replication of kinetoplast DNA, a subject that our lab has studied for many years. Our knowledge of kinetoplast DNA replication has depended mostly upon the investigation of the biochemical properties and intramitochondrial localisation of replication proteins and enzymes as well as a study of the structure and dynamics of kinetoplast DNA replication intermediates. We will first review the properties of the characterised kinetoplast DNA replication proteins and then describe our current model for kinetoplast DNA replication.</style></abstract><issue><style face="normal" font="default" size="100%">5-6</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/11334929?dopt=Abstract</style></custom1></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Lu, H</style></author><author><style face="normal" font="default" size="100%">Burand, J P</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Replication of the gonad-specific virus Hz-2V in Ld652Y cells mimics replication in vivo.</style></title><secondary-title><style face="normal" font="default" size="100%">J Invertebr Pathol</style></secondary-title><alt-title><style face="normal" font="default" size="100%">J. Invertebr. Pathol.</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Animals</style></keyword><keyword><style  face="normal" font="default" size="100%">Baculoviridae</style></keyword><keyword><style  face="normal" font="default" size="100%">Cell Line</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA Replication</style></keyword><keyword><style  face="normal" font="default" size="100%">Lepidoptera</style></keyword><keyword><style  face="normal" font="default" size="100%">Molecular Mimicry</style></keyword><keyword><style  face="normal" font="default" size="100%">Time Factors</style></keyword><keyword><style  face="normal" font="default" size="100%">Virus Cultivation</style></keyword><keyword><style  face="normal" font="default" size="100%">Virus Replication</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2001</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2001 Jan</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">77</style></volume><pages><style face="normal" font="default" size="100%">44-50</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">A newly discovered, nonoccluded insect virus, known as gonad-specific virus or Hz-2V, was found to replicate differently in two insect cell lines derived from ovarian tissues (Tn-368 cells from Trichoplusia ni and Ld652Y from Lymantria dispar). Differences between these two cell lines were observed in virus plaque forming ability, rate of viral DNA replication, time course of infectious virus production, and the mechanism of virus release from infected cells. Replication of Hz-2V in Ld652Y cells was more productive and more closely resembled in vivo virus replication.</style></abstract><issue><style face="normal" font="default" size="100%">1</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/11161993?dopt=Abstract</style></custom1></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Klingbeil, M M</style></author><author><style face="normal" font="default" size="100%">Drew, M E</style></author><author><style face="normal" font="default" size="100%">Liu, Y</style></author><author><style face="normal" font="default" size="100%">Morris, J C</style></author><author><style face="normal" font="default" size="100%">Motyka, S A</style></author><author><style face="normal" font="default" size="100%">Saxowsky, T T</style></author><author><style face="normal" font="default" size="100%">Wang, Z</style></author><author><style face="normal" font="default" size="100%">Englund, P T</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Unlocking the secrets of trypanosome kinetoplast DNA network replication.</style></title><secondary-title><style face="normal" font="default" size="100%">Protist</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Protist</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Animals</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA Replication</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA, Kinetoplast</style></keyword><keyword><style  face="normal" font="default" size="100%">Protozoan Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Trypanosoma brucei brucei</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2001</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2001 Dec</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">152</style></volume><pages><style face="normal" font="default" size="100%">255-62</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><issue><style face="normal" font="default" size="100%">4</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/11822657?dopt=Abstract</style></custom1></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Cox, M M</style></author><author><style face="normal" font="default" size="100%">Goodman, M F</style></author><author><style face="normal" font="default" size="100%">Kreuzer, K N</style></author><author><style face="normal" font="default" size="100%">Sherratt, D J</style></author><author><style face="normal" font="default" size="100%">Sandler, S J</style></author><author><style face="normal" font="default" size="100%">Marians, K J</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">The importance of repairing stalled replication forks.</style></title><secondary-title><style face="normal" font="default" size="100%">Nature</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Nature</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Bacteria</style></keyword><keyword><style  face="normal" font="default" size="100%">Bacterial Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Chromosomes, Bacterial</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA Replication</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA, Bacterial</style></keyword><keyword><style  face="normal" font="default" size="100%">Escherichia coli</style></keyword><keyword><style  face="normal" font="default" size="100%">Recombination, Genetic</style></keyword><keyword><style  face="normal" font="default" size="100%">Replication Origin</style></keyword><keyword><style  face="normal" font="default" size="100%">SOS Response (Genetics)</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2000</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2000 Mar 2</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">404</style></volume><pages><style face="normal" font="default" size="100%">37-41</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The bacterial SOS response to unusual levels of DNA damage has been recognized and studied for several decades. Pathways for re-establishing inactivated replication forks under normal growth conditions have received far less attention. In bacteria growing aerobically in the absence of SOS-inducing conditions, many replication forks encounter DNA damage, leading to inactivation. The pathways for fork reactivation involve the homologous recombination systems, are nonmutagenic, and integrate almost every aspect of DNA metabolism. On a frequency-of-use basis, these pathways represent the main function of bacterial DNA recombination systems, as well as the main function of a number of other enzymatic systems that are associated with replication and site-specific recombination.</style></abstract><issue><style face="normal" font="default" size="100%">6773</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/10716434?dopt=Abstract</style></custom1></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Sandler, S J</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Multiple genetic pathways for restarting DNA replication forks in Escherichia coli K-12.</style></title><secondary-title><style face="normal" font="default" size="100%">Genetics</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Genetics</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Base Sequence</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA Primers</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA Replication</style></keyword><keyword><style  face="normal" font="default" size="100%">Escherichia coli</style></keyword><keyword><style  face="normal" font="default" size="100%">Genes, Lethal</style></keyword><keyword><style  face="normal" font="default" size="100%">Mutation</style></keyword><keyword><style  face="normal" font="default" size="100%">Polymerase Chain Reaction</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2000</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2000 Jun</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">155</style></volume><pages><style face="normal" font="default" size="100%">487-97</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">In Escherichia coli, the primosome assembly proteins, PriA, PriB, PriC, DnaT, DnaC, DnaB, and DnaG, are thought to help to restart DNA replication forks at recombinational intermediates. Redundant functions between priB and priC and synthetic lethality between priA2::kan and rep3 mutations raise the possibility that there may be multiple pathways for restarting replication forks in vivo. Herein, it is shown that priA2::kan causes synthetic lethality when placed in combination with either Deltarep::kan or priC303:kan. These determinations were made using a nonselective P1 transduction-based viability assay. Two different priA2::kan suppressors (both dnaC alleles) were tested for their ability to rescue the priA-priC and priA-rep double mutant lethality. Only dnaC809,820 (and not dnaC809) could rescue the lethality in each case. Additionally, it was shown that the absence of the 3'-5' helicase activity of both PriA and Rep is not the critical missing function that causes the synthetic lethality in the rep-priA double mutant. One model proposes that replication restart at recombinational intermediates occurs by both PriA-dependent and PriA-independent pathways. The PriA-dependent pathways require at least priA and priB or priC, and the PriA-independent pathway requires at least priC and rep. It is further hypothesized that the dnaC809 suppression of priA2::kan requires priC and rep, whereas dnaC809,820 suppression of priA2::kan does not.</style></abstract><issue><style face="normal" font="default" size="100%">2</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/10835375?dopt=Abstract</style></custom1></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Sandler, S J</style></author><author><style face="normal" font="default" size="100%">Marians, K J</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Role of PriA in replication fork reactivation in Escherichia coli.</style></title><secondary-title><style face="normal" font="default" size="100%">J Bacteriol</style></secondary-title><alt-title><style face="normal" font="default" size="100%">J. Bacteriol.</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Bacterial Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA Primase</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA Repair</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA Replication</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA, Bacterial</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA-Binding Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Escherichia coli</style></keyword><keyword><style  face="normal" font="default" size="100%">Escherichia coli Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Models, Genetic</style></keyword><keyword><style  face="normal" font="default" size="100%">Replication Protein A</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2000</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2000 Jan</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">182</style></volume><pages><style face="normal" font="default" size="100%">9-13</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><issue><style face="normal" font="default" size="100%">1</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/10613856?dopt=Abstract</style></custom1></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Sandler, S J</style></author><author><style face="normal" font="default" size="100%">Marians, K J</style></author><author><style face="normal" font="default" size="100%">Zavitz, K H</style></author><author><style face="normal" font="default" size="100%">Coutu, J</style></author><author><style face="normal" font="default" size="100%">Parent, M A</style></author><author><style face="normal" font="default" size="100%">Clark, A J</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">dnaC mutations suppress defects in DNA replication- and recombination-associated functions in priB and priC double mutants in Escherichia coli K-12.</style></title><secondary-title><style face="normal" font="default" size="100%">Mol Microbiol</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Mol. Microbiol.</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Bacterial Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Bacteriophage mu</style></keyword><keyword><style  face="normal" font="default" size="100%">Cell Division</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA Replication</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA, Bacterial</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA-Binding Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Escherichia coli</style></keyword><keyword><style  face="normal" font="default" size="100%">Escherichia coli Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Mutation</style></keyword><keyword><style  face="normal" font="default" size="100%">Phenotype</style></keyword><keyword><style  face="normal" font="default" size="100%">Recombination, Genetic</style></keyword><keyword><style  face="normal" font="default" size="100%">Replication Protein A</style></keyword><keyword><style  face="normal" font="default" size="100%">SOS Response (Genetics)</style></keyword><keyword><style  face="normal" font="default" size="100%">Substrate Specificity</style></keyword><keyword><style  face="normal" font="default" size="100%">Suppression, Genetic</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1999</style></year><pub-dates><date><style  face="normal" font="default" size="100%">1999 Oct</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">34</style></volume><pages><style face="normal" font="default" size="100%">91-101</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">PriA, PriB and PriC were originally discovered as proteins essential for the PhiX174 in vitro DNA replication system. Recent studies have shown that PriA mutants are poorly viable, have high basal levels of SOS expression (SOSH), are recombination deficient (Rec-), sensitive to UV irradiation (UVS) and sensitive to rich media. These data suggest that priA's role may be more complex than previously thought and may involve both DNA replication and homologous recombination. Based on the PhiX174 system, mutations in priB and priC should cause phenotypes like those seen in priA2:kan mutants. To test this, mutations in priB and priC were constructed. We found that, contrary to the PhiX174 model, del(priB)302 and priC303:kan mutants have almost wild-type phenotypes. Most unexpectedly, we then found that the priBC double mutant had very poor viability and/or a slow growth rate (even less than a priA2:kan mutant). This suggests that priB and priC have a redundant and important role in Escherichia coli. The priA2:kan suppressor, dnaC809, partially suppressed the poor viability/slow growth phenotype of the priBC double mutant. The resulting triple mutant (priBC dnaC809 ) had small colony size, recombination deficiency and levels of SOS expression similar to a priA2:kan mutant. The priBC dnaC809 mutant, however, was moderately UVR and had good viability, unlike a priA2:kan mutant. Additional mutations in the triple mutant were selected to suppress the slow growth phenotype. One suppressor restored all phenotypes tested to nearly wild-type levels. This mutation was identified as dnaC820 (K178N) [mapping just downstream of dnaC809 (E176G)]. Experiments suggest that dnaC820 makes dnaC809 suppression of priA and or priBC mutants priB and or priC independent. A model is proposed for the roles of these proteins in terms of restarting collapsed replication forks from recombinational intermediates.</style></abstract><issue><style face="normal" font="default" size="100%">1</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/10540288?dopt=Abstract</style></custom1></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Liu, J</style></author><author><style face="normal" font="default" size="100%">Xu, L</style></author><author><style face="normal" font="default" size="100%">Sandler, S J</style></author><author><style face="normal" font="default" size="100%">Marians, K J</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Replication fork assembly at recombination intermediates is required for bacterial growth.</style></title><secondary-title><style face="normal" font="default" size="100%">Proc Natl Acad Sci U S A</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Proc. Natl. Acad. Sci. U.S.A.</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Bacteria</style></keyword><keyword><style  face="normal" font="default" size="100%">Bacteriophage phi X 174</style></keyword><keyword><style  face="normal" font="default" size="100%">Base Sequence</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA Polymerase III</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA Replication</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA-Binding Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Escherichia coli</style></keyword><keyword><style  face="normal" font="default" size="100%">Molecular Sequence Data</style></keyword><keyword><style  face="normal" font="default" size="100%">Oligodeoxyribonucleotides</style></keyword><keyword><style  face="normal" font="default" size="100%">Open Reading Frames</style></keyword><keyword><style  face="normal" font="default" size="100%">Recombination, Genetic</style></keyword><keyword><style  face="normal" font="default" size="100%">Replication Protein A</style></keyword><keyword><style  face="normal" font="default" size="100%">Templates, Genetic</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1999</style></year><pub-dates><date><style  face="normal" font="default" size="100%">1999 Mar 30</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">96</style></volume><pages><style face="normal" font="default" size="100%">3552-5</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">PriA, a 3' --&gt; 5' DNA helicase, directs assembly of a primosome on some bacteriophage and plasmid DNAs. Primosomes are multienzyme replication machines that contribute both the DNA-unwinding and Okazaki fragment-priming functions at the replication fork. The role of PriA in chromosomal replication is unclear. The phenotypes of priA null mutations suggest that the protein participates in replication restart at recombination intermediates. We show here that PriA promotes replication fork assembly at a D loop, an intermediate formed during initiation of homologous recombination. We also show that DnaC810, encoded by a naturally arising intergenic suppressor allele of the priA2::kan mutation, bypasses the need for PriA during replication fork assembly at D loops in vitro. These findings underscore the essentiality of replication fork restart at recombination intermediates under normal growth conditions in bacteria.</style></abstract><issue><style face="normal" font="default" size="100%">7</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/10097074?dopt=Abstract</style></custom1></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Sandler, S J</style></author><author><style face="normal" font="default" size="100%">Samra, H S</style></author><author><style face="normal" font="default" size="100%">Clark, A J</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Differential suppression of priA2::kan phenotypes in Escherichia coli K-12 by mutations in priA, lexA, and dnaC.</style></title><secondary-title><style face="normal" font="default" size="100%">Genetics</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Genetics</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Bacterial Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Bacteriophage phi X 174</style></keyword><keyword><style  face="normal" font="default" size="100%">beta-Galactosidase</style></keyword><keyword><style  face="normal" font="default" size="100%">Chromosomes, Bacterial</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA Helicases</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA Replication</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA-Binding Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Dose-Response Relationship, Radiation</style></keyword><keyword><style  face="normal" font="default" size="100%">Escherichia coli</style></keyword><keyword><style  face="normal" font="default" size="100%">Escherichia coli Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Genes, Bacterial</style></keyword><keyword><style  face="normal" font="default" size="100%">Genetic Markers</style></keyword><keyword><style  face="normal" font="default" size="100%">Mutagenesis</style></keyword><keyword><style  face="normal" font="default" size="100%">Phenotype</style></keyword><keyword><style  face="normal" font="default" size="100%">Recombination, Genetic</style></keyword><keyword><style  face="normal" font="default" size="100%">Replication Protein A</style></keyword><keyword><style  face="normal" font="default" size="100%">Repressor Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Serine Endopeptidases</style></keyword><keyword><style  face="normal" font="default" size="100%">Suppression, Genetic</style></keyword><keyword><style  face="normal" font="default" size="100%">Transduction, Genetic</style></keyword><keyword><style  face="normal" font="default" size="100%">Ultraviolet Rays</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1996</style></year><pub-dates><date><style  face="normal" font="default" size="100%">1996 May</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">143</style></volume><pages><style face="normal" font="default" size="100%">5-13</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">First identified as an essential component of the phi X174 in vitro DNA replication system, PriA has ATPase, helicase, translocase, and primosome-assembly activities. priA1::kan strains of Escherichia coli are sensitive to UV irradiation, deficient in homologous recombination following transduction, and filamentous. priA2::kan strains have eightfold higher levels of uninduced SOS expression than wild type. We show that (1) priA1::kan strains have eightfold higher levels of uninduced SOS expression, (2) priA2::kan strains are UVS and Rec-, (3) lexA3 suppresses the high basal levels of SOS expression of a priA2::kan strain, and (4) plasmid-encoded priA300 (K230R), a mutant allele retaining only the primosome-assembly activity of priA+, restores both UVR and Rec+ phenotypes to a priA2::kan strain. Finally, we have isolated 17 independent UVR Rec+ revertants of priA2::kan strains that carry extragenic suppressors. All 17 map in the C-terminal half of the dnaC gene. DnaC loads the DnaB helicase onto DNA as a prelude for primosome assembly and DNA replication. We conclude that priA's primosome-assembly activity is essential for DNA repair and recombination and that the dnaC suppressor mutations allow these processes to occur in the absence of priA.</style></abstract><issue><style face="normal" font="default" size="100%">1</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/8722757?dopt=Abstract</style></custom1></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Clark, A J</style></author><author><style face="normal" font="default" size="100%">Sandler, S J</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Homologous genetic recombination: the pieces begin to fall into place.</style></title><secondary-title><style face="normal" font="default" size="100%">Crit Rev Microbiol</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Crit. Rev. Microbiol.</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">DNA Replication</style></keyword><keyword><style  face="normal" font="default" size="100%">Escherichia coli</style></keyword><keyword><style  face="normal" font="default" size="100%">Genes, Bacterial</style></keyword><keyword><style  face="normal" font="default" size="100%">Rec A Recombinases</style></keyword><keyword><style  face="normal" font="default" size="100%">Recombination, Genetic</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1994</style></year><pub-dates><date><style  face="normal" font="default" size="100%">1994</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">20</style></volume><pages><style face="normal" font="default" size="100%">125-42</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">One of the authors (AJC) acknowledges with gratitude the important role Fernando Bastarrachea played in the author's discovery that E. coli could carry out homologous genetic recombination by multiple pathways. This in turn led to the discovery of several genes, including recF, recO, and recR, whose role in recombination would not otherwise have been detected. Subsequent genetic and biochemical studies have led to a general formulation in which there are multiple nucleolytic ways to achieve a presynaptic intermediate bound to RecA protein. Postsynaptic events in the general formulation occur by means of multiple branch migration enzymes to form Holliday DNA structures and a specific nuclease to cleave them. The general formulation is built on synapsis catalyzed by RecA protein. A second RecA-independent synapsis catalyzed by RecT (and RecE?) protein is now under study and a third type independent of both RecA and RecT has apparently been discovered. How these will affect the general formulation remains to be seen. Some proteins, most prominently RecF, RecO, and RecR, have no role in the general formulation. The hypothesis is presented that these proteins act as a switch between replication and recombination by helping to convert replication to recombination intermediates. Universality of the general formulation is supported by the widespread occurrence of recA, recB, recC, and recD genes among bacteria. Recent discovery of recA-like genes in several eukaryotes further supports its universality. We have contributed additional support by sequencing a recA-like gene from an archaeal species, thus making it plausible that the mechanism of synapsis worked out for E. coli RecA protein will hold for all three organismal domains. The boundaries of the puzzle of homologous genetic recombination therefore seem complete and the pieces to the complex picture they encompass are falling into place.</style></abstract><issue><style face="normal" font="default" size="100%">2</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/8080625?dopt=Abstract</style></custom1></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Blanar, M A</style></author><author><style face="normal" font="default" size="100%">Sandler, S J</style></author><author><style face="normal" font="default" size="100%">Armengod, M E</style></author><author><style face="normal" font="default" size="100%">Ream, L W</style></author><author><style face="normal" font="default" size="100%">Clark, A J</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Molecular analysis of the recF gene of Escherichia coli.</style></title><secondary-title><style face="normal" font="default" size="100%">Proc Natl Acad Sci U S A</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Proc. Natl. Acad. Sci. U.S.A.</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Amino Acid Sequence</style></keyword><keyword><style  face="normal" font="default" size="100%">Bacterial Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Base Sequence</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA Repair</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA Replication</style></keyword><keyword><style  face="normal" font="default" size="100%">Escherichia coli</style></keyword><keyword><style  face="normal" font="default" size="100%">Genes, Bacterial</style></keyword><keyword><style  face="normal" font="default" size="100%">Molecular Weight</style></keyword><keyword><style  face="normal" font="default" size="100%">Mutation</style></keyword><keyword><style  face="normal" font="default" size="100%">Plasmids</style></keyword><keyword><style  face="normal" font="default" size="100%">Recombination, Genetic</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1984</style></year><pub-dates><date><style  face="normal" font="default" size="100%">1984 Aug</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">81</style></volume><pages><style face="normal" font="default" size="100%">4622-6</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">We analyzed the nucleotide sequence of a 1.325-kilobase region of wild-type Escherichia coli containing a functional recF gene and six Tn3 mutations that inactivate recF. The analysis shows a potentially translatable reading frame of 1071 nucleotides, which is interrupted by all six insertions. A protein of 40.5 kilodaltons would result from translation of the open reading frame, and a radioactive band of protein of an apparent molecular weight of approximately 40 kilodaltons was seen by the maxicell method using a recF+ plasmid. Putative truncated peptides were seen when two recF::Tn3 mutant plasmids were used. Differential expression of dnaN and recF from a common promoter was noted. recF332::Tn3 was transferred to the chromosome where, in hemizygous condition, it produced UV sensitivity indistinguishable from that produced by two presumed recF point mutations.</style></abstract><issue><style face="normal" font="default" size="100%">15</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/6379647?dopt=Abstract</style></custom1></record></records></xml>