<?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%">Handa, Naofumi</style></author><author><style face="normal" font="default" size="100%">Amitani, Ichiro</style></author><author><style face="normal" font="default" size="100%">Gumlaw, Nathan</style></author><author><style face="normal" font="default" size="100%">Sandler, Steven J</style></author><author><style face="normal" font="default" size="100%">Kowalczykowski, Stephen C</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Single molecule analysis of a red fluorescent RecA protein reveals a defect in nucleoprotein filament nucleation that relates to its reduced biological functions.</style></title><secondary-title><style face="normal" font="default" size="100%">J Biol Chem</style></secondary-title><alt-title><style face="normal" font="default" size="100%">J. Biol. Chem.</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Cell Nucleus</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA, Single-Stranded</style></keyword><keyword><style  face="normal" font="default" size="100%">Escherichia coli</style></keyword><keyword><style  face="normal" font="default" size="100%">Hydrogen-Ion Concentration</style></keyword><keyword><style  face="normal" font="default" size="100%">Kinetics</style></keyword><keyword><style  face="normal" font="default" size="100%">Luminescent Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Nucleoproteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Plasmids</style></keyword><keyword><style  face="normal" font="default" size="100%">Protein Binding</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><keyword><style  face="normal" font="default" size="100%">Sensitivity and Specificity</style></keyword><keyword><style  face="normal" font="default" size="100%">Ultraviolet Rays</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 Jul 10</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">284</style></volume><pages><style face="normal" font="default" size="100%">18664-73</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Fluorescent fusion proteins are exceedingly useful for monitoring protein localization in situ or visualizing protein behavior at the single molecule level. Unfortunately, some proteins are rendered inactive by the fusion. To circumvent this problem, we fused a hyperactive RecA protein (RecA803 protein) to monomeric red fluorescent protein (mRFP1) to produce a functional protein (RecA-RFP) that is suitable for in vivo and in vitro analysis. In vivo, the RecA-RFP partially restores UV resistance, conjugational recombination, and SOS induction to recA(-) cells. In vitro, the purified RecA-RFP protein forms a nucleoprotein filament whose k(cat) for single-stranded DNA-dependent ATPase activity is reduced approximately 3-fold relative to wild-type protein, and which is largely inhibited by single-stranded DNA-binding protein. However, RecA protein is also a dATPase; dATP supports RecA-RFP nucleoprotein filament formation in the presence of single-stranded DNA-binding protein. Furthermore, as for the wild-type protein, the activities of RecA-RFP are further enhanced by shifting the pH to 6.2. As a consequence, RecA-RFP is proficient for DNA strand exchange with dATP or at lower pH. Finally, using single molecule visualization, RecA-RFP was seen to assemble into a continuous filament on duplex DNA, and to extend the DNA approximately 1.7-fold. Consistent with its attenuated activities, RecA-RFP nucleates onto double-stranded DNA approximately 3-fold more slowly than the wild-type protein, but still requires approximately 3 monomers to form the rate-limited nucleus needed for filament assembly. Thus, RecA-RFP reveals that its attenuated biological functions correlate with a reduced frequency of nucleoprotein filament nucleation at the single molecule level.</style></abstract><issue><style face="normal" font="default" size="100%">28</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/19419960?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%">Sandler, Steven J</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Requirements for ATP binding and hydrolysis in RecA function in Escherichia coli.</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%">Adenosine Triphosphate</style></keyword><keyword><style  face="normal" font="default" size="100%">Chromosomes, 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%">Hydrolysis</style></keyword><keyword><style  face="normal" font="default" size="100%">Mutation</style></keyword><keyword><style  face="normal" font="default" size="100%">Protein Binding</style></keyword><keyword><style  face="normal" font="default" size="100%">Rec A Recombinases</style></keyword><keyword><style  face="normal" font="default" size="100%">Ultraviolet Rays</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 Mar</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">67</style></volume><pages><style face="normal" font="default" size="100%">1347-59</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">RecA is essential for recombination, DNA repair and SOS induction in Escherichia coli. ATP hydrolysis is known to be important for RecA's roles in recombination and DNA repair. In vitro reactions modelling SOS induction minimally require ssDNA and non-hydrolyzable ATP analogues. This predicts that ATP hydrolysis will not be required for SOS induction in vivo. The requirement of ATP binding and hydrolysis for SOS induction in vivo is tested here through the study of recA4159 (K72A) and recA2201 (K72R). RecA4159 is thought to have reduced affinity for ATP. RecA2201 binds, but does not hydrolyse ATP. Neither mutant was able to induce SOS expression after UV irradiation. RecA2201, unlike RecA4159, could form filaments on DNA and storage structures as measured with RecA-GFP. RecA2201 was able to form hybrid filaments and storage structures and was either recessive or dominant to RecA(+), depending on the ratio of the two proteins. RecA4159 was unable to enter RecA(+) filaments on DNA or storage structures and was recessive to RecA(+). It is concluded that ATP hydrolysis is essential for SOS induction. It is proposed that ATP binding is essential for storage structure formation and ability to interact with other RecA proteins in a filament.</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/18298444?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></records></xml>