@article {826,
	title = {Effects of mutations involving cell division, recombination, and chromosome dimer resolution on a priA2::kan mutant.},
	journal = {Proc Natl Acad Sci U S A},
	volume = {98},
	year = {2001},
	month = {2001 Jul 17},
	pages = {8203-10},
	abstract = {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{\textquoteright},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.},
	keywords = {Adenosine Triphosphatases, Bacterial Proteins, Cell Division, Chromosomes, Bacterial, Dimerization, DNA Helicases, Endodeoxyribonucleases, Escherichia coli, Escherichia coli Proteins, Exodeoxyribonuclease V, Exodeoxyribonucleases, Gene Expression, Membrane Proteins, Mutagenesis, Rec A Recombinases, Recombination, Genetic, SOS Response (Genetics)},
	issn = {0027-8424},
	doi = {10.1073/pnas.121007698},
	author = {McCool, J D and Sandler, S J}
}
@article {825,
	title = {PriA mutations that affect PriA-PriC function during replication restart.},
	journal = {Mol Microbiol},
	volume = {41},
	year = {2001},
	month = {2001 Aug},
	pages = {697-704},
	abstract = {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{\textquoteright}s helicase activity is important for the PriA-PriC pathway of replication restart.},
	keywords = {Bacterial Proteins, Bacteriophage mu, Cell Division, DNA Replication, DNA-Binding Proteins, Escherichia coli, Escherichia coli Proteins, Genes, Lethal, Genotype, Models, Biological, Mutation, Missense, Phenotype, Replication Protein A, SOS Response (Genetics), Ultraviolet Rays},
	issn = {0950-382X},
	author = {Sandler, S J and McCool, J D and Do, T T and Johansen, R U}
}
@article {830,
	title = {dnaC mutations suppress defects in DNA replication- and recombination-associated functions in priB and priC double mutants in Escherichia coli K-12.},
	journal = {Mol Microbiol},
	volume = {34},
	year = {1999},
	month = {1999 Oct},
	pages = {91-101},
	abstract = {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{\textquoteright}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.},
	keywords = {Bacterial Proteins, Bacteriophage mu, Cell Division, DNA Replication, DNA, Bacterial, DNA-Binding Proteins, Escherichia coli, Escherichia coli Proteins, Mutation, Phenotype, Recombination, Genetic, Replication Protein A, SOS Response (Genetics), Substrate Specificity, Suppression, Genetic},
	issn = {0950-382X},
	author = {Sandler, S J and Marians, K J and Zavitz, K H and Coutu, J and Parent, M A and Clark, A J}
}
