<?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%">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%">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%">Methé, B A</style></author><author><style face="normal" font="default" size="100%">Nelson, K E</style></author><author><style face="normal" font="default" size="100%">Eisen, J A</style></author><author><style face="normal" font="default" size="100%">Paulsen, I T</style></author><author><style face="normal" font="default" size="100%">Nelson, W</style></author><author><style face="normal" font="default" size="100%">Heidelberg, J F</style></author><author><style face="normal" font="default" size="100%">Wu, D</style></author><author><style face="normal" font="default" size="100%">Wu, M</style></author><author><style face="normal" font="default" size="100%">Ward, N</style></author><author><style face="normal" font="default" size="100%">Beanan, M J</style></author><author><style face="normal" font="default" size="100%">Dodson, R J</style></author><author><style face="normal" font="default" size="100%">Madupu, R</style></author><author><style face="normal" font="default" size="100%">Brinkac, L M</style></author><author><style face="normal" font="default" size="100%">Daugherty, S C</style></author><author><style face="normal" font="default" size="100%">DeBoy, R T</style></author><author><style face="normal" font="default" size="100%">Durkin, A S</style></author><author><style face="normal" font="default" size="100%">Gwinn, M</style></author><author><style face="normal" font="default" size="100%">Kolonay, J F</style></author><author><style face="normal" font="default" size="100%">Sullivan, S A</style></author><author><style face="normal" font="default" size="100%">Haft, D H</style></author><author><style face="normal" font="default" size="100%">Selengut, J</style></author><author><style face="normal" font="default" size="100%">Davidsen, T M</style></author><author><style face="normal" font="default" size="100%">Zafar, N</style></author><author><style face="normal" font="default" size="100%">White, O</style></author><author><style face="normal" font="default" size="100%">Tran, B</style></author><author><style face="normal" font="default" size="100%">Romero, C</style></author><author><style face="normal" font="default" size="100%">Forberger, H A</style></author><author><style face="normal" font="default" size="100%">Weidman, J</style></author><author><style face="normal" font="default" size="100%">Khouri, H</style></author><author><style face="normal" font="default" size="100%">Feldblyum, T V</style></author><author><style face="normal" font="default" size="100%">Utterback, T R</style></author><author><style face="normal" font="default" size="100%">Van Aken, S E</style></author><author><style face="normal" font="default" size="100%">Lovley, D R</style></author><author><style face="normal" font="default" size="100%">Fraser, C M</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Genome of Geobacter sulfurreducens: metal reduction in subsurface environments.</style></title><secondary-title><style face="normal" font="default" size="100%">Science</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Science</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Acetates</style></keyword><keyword><style  face="normal" font="default" size="100%">Acetyl Coenzyme A</style></keyword><keyword><style  face="normal" font="default" size="100%">Aerobiosis</style></keyword><keyword><style  face="normal" font="default" size="100%">Anaerobiosis</style></keyword><keyword><style  face="normal" font="default" size="100%">Bacterial Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Carbon</style></keyword><keyword><style  face="normal" font="default" size="100%">Chemotaxis</style></keyword><keyword><style  face="normal" font="default" size="100%">Chromosomes, Bacterial</style></keyword><keyword><style  face="normal" font="default" size="100%">Cytochromes c</style></keyword><keyword><style  face="normal" font="default" size="100%">Electron Transport</style></keyword><keyword><style  face="normal" font="default" size="100%">Energy Metabolism</style></keyword><keyword><style  face="normal" font="default" size="100%">Genes, Bacterial</style></keyword><keyword><style  face="normal" font="default" size="100%">Genes, Regulator</style></keyword><keyword><style  face="normal" font="default" size="100%">Genome, Bacterial</style></keyword><keyword><style  face="normal" font="default" size="100%">Geobacter</style></keyword><keyword><style  face="normal" font="default" size="100%">Hydrogen</style></keyword><keyword><style  face="normal" font="default" size="100%">Metals</style></keyword><keyword><style  face="normal" font="default" size="100%">Movement</style></keyword><keyword><style  face="normal" font="default" size="100%">Open Reading Frames</style></keyword><keyword><style  face="normal" font="default" size="100%">Oxidation-Reduction</style></keyword><keyword><style  face="normal" font="default" size="100%">Phylogeny</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2003</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2003 Dec 12</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">302</style></volume><pages><style face="normal" font="default" size="100%">1967-9</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The complete genome sequence of Geobacter sulfurreducens, a delta-proteobacterium, reveals unsuspected capabilities, including evidence of aerobic metabolism, one-carbon and complex carbon metabolism, motility, and chemotactic behavior. These characteristics, coupled with the possession of many two-component sensors and many c-type cytochromes, reveal an ability to create alternative, redundant, electron transport networks and offer insights into the process of metal ion reduction in subsurface environments. As well as playing roles in the global cycling of metals and carbon, this organism clearly has the potential for use in bioremediation of radioactive metals and in the generation of electricity.</style></abstract><issue><style face="normal" font="default" size="100%">5652</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/14671304?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, J D</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%">Effects of mutations involving cell division, recombination, and chromosome dimer resolution on a priA2::kan mutant.</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%">Adenosine Triphosphatases</style></keyword><keyword><style  face="normal" font="default" size="100%">Bacterial Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Cell Division</style></keyword><keyword><style  face="normal" font="default" size="100%">Chromosomes, Bacterial</style></keyword><keyword><style  face="normal" font="default" size="100%">Dimerization</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA Helicases</style></keyword><keyword><style  face="normal" font="default" size="100%">Endodeoxyribonucleases</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%">Exodeoxyribonuclease V</style></keyword><keyword><style  face="normal" font="default" size="100%">Exodeoxyribonucleases</style></keyword><keyword><style  face="normal" font="default" size="100%">Gene Expression</style></keyword><keyword><style  face="normal" font="default" size="100%">Membrane Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Mutagenesis</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%">SOS Response (Genetics)</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 Jul 17</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">98</style></volume><pages><style face="normal" font="default" size="100%">8203-10</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Recombinational repair of replication forks can occur either to a crossover (XO) or noncrossover (non-XO) depending on Holliday junction resolution. Once the fork is repaired by recombination, PriA is important for restarting these forks in Escherichia coli. PriA mutants are Rec(-) and UV sensitive and have poor viability and 10-fold elevated basal levels of SOS expression. PriA sulB mutant cells and their nucleoids were studied by differential interference contrast and fluorescence microscopy of 4',6-diamidino-2-phenylindole-stained log phase cells. Two populations of cells were seen. Eighty four percent appeared like wild type, and 16% of the cells were filamented and had poorly partitioned chromosomes (Par(-)). To probe potential mechanisms leading to the two populations of cells, mutations were added to the priA sulB mutant. Mutating sulA or introducing lexA3 decreased, but did not eliminate filamentation or defects in partitioning. Mutating either recA or recB virtually eliminated the Par(-) phenotype. Filamentation in the recB mutant decreased to 3%, but increased to 28% in the recA mutant. The ability to resolve and/or branch migrate Holliday junctions also appeared crucial in the priA mutant because removing either recG or ruvC was lethal. Lastly, it was tested whether the ability to resolve chromosome dimers caused by XOs was important in a priA mutant by mutating dif and the C-terminal portion of ftsK. Mutation of dif showed no change in phenotype whereas ftsK1cat was lethal with priA2kan. A model is proposed where the PriA-independent pathway of replication restart functions at forks that have been repaired to non-XOs.</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/11459954?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><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%">Sandler, S J</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%">Use of high and low level overexpression plasmids to test mutant alleles of the recF gene of Escherichia coli K-12 for partial activity.</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%">Alleles</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%">Chromosomes, Bacterial</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA Repair</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</style></keyword><keyword><style  face="normal" font="default" size="100%">Genes, Bacterial</style></keyword><keyword><style  face="normal" font="default" size="100%">Molecular Sequence Data</style></keyword><keyword><style  face="normal" font="default" size="100%">Mutagenesis, Site-Directed</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%">Plasmids</style></keyword><keyword><style  face="normal" font="default" size="100%">Radiation Tolerance</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%">1993</style></year><pub-dates><date><style  face="normal" font="default" size="100%">1993 Nov</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">135</style></volume><pages><style face="normal" font="default" size="100%">643-54</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">We showed that sufficient overexpression of the wild-type recF gene interfered with three normal cell functions: (1) UV induction of transcription from the LexA-protein-repressed sulA promoter, (2) UV resistance and (3) cell viability at 42 degrees. To show this, we altered a low-level overexpressing recF+ plasmid with a set of structurally neutral mutations that increased the rate of expression of recF. The resulting high-level overexpressing plasmid interfered with UV induction of the sulA promoter, as did the low-level overexpressing plasmid. It also reduced UV resistance more than its low level progenitor and decreased viability at 42 degrees, an effect not seen with the low-level plasmid. We used the high-level plasmid to test four recF structural mutations for residual activity. The structural alleles consisted of an insertion mutation, two single amino acid substitution mutations and a double amino acid substitution mutation. On the Escherichia coli chromosome the three substitution mutations acted similarly to a recF deletion in reducing UV resistance in a recB21 recC22 sbcB15 sbcC201 genetic background. By this test, therefore, all three appeared to be null alleles. Measurements of conjugational recombination revealed, however, that the three substitution mutations may have residual activity. On the high-level overexpressing plasmid all three substitution mutations definitely showed partial activity. By contrast, the insertion mutation on the high-level overexpressing plasmid showed no partial activity and can be considered a true null mutation. One of the substitutions, recF143, showed a property attributable to a leaky mutation. Another substitution, recF4101, may block selectively two of the three interference phenotypes, thus allowing us to infer a mechanism for them.</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/8293970?dopt=Abstract</style></custom1></record></records></xml>