<?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%">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%">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></records></xml>