Primosome assembly requirement for replication restart in the Escherichia coli holDG10 replication mutant.
In this report, we study the role of pre-primosome proteins in a strain in which the frequency of replication arrest is increased because of a mutation in a replication protein. The holDG10 mutant was used, in which replication restart involves replication fork reversal. As expected, PriA primosome assembly function is essential for growth of the holDG10 mutant. The priA300 mutation, which inactivates only the helicase function of PriA in vitro, and priB inactivation strongly impair viability. In contrast, priC inactivation has no effect. Therefore, PriB is more important than PriC for PriA-dependent replication fork restart in vivo. The gain of function mutation dnaC809 restores the viability of holDG10 priA and holDG10 priB mutants only to some extent. The dnaC809 820 double mutation restores full viability to the holDG10 mutant lacking either PriA or PriB. Similarly to the holDG10 single mutant, the holDG10 priA dnaC809 820 strain is depend-ent on RecBC for viability, indicating that facilitating primosome assembly using the dnaC809 820 mutation does not allow bypass of replication fork reversal.
Flores
Maria Jose
MJ
Laboratoire de Génétique Microbienne, Institut National de la Recherche Agronomique, Jouy en Josas, France.
Ehrlich
S Dusko
SD
Michel
Bénédicte
B
D000251:Adenosine Triphosphatases / Q000502:physiology; D000483:Alleles; D004265:DNA Helicases / Q000502:physiology; D004261:DNA Replication / Q000235:genetics / Q000502:physiology*; D004269:DNA, Bacterial / Q000096:biosynthesis / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000502:physiology*; D004926:Escherichia coli / Q000235:genetics* / Q000502:physiology / Q000648:ultrastructure; D029968:Escherichia coli Proteins / Q000235:genetics / Q000502:physiology*; D005816:Genetic Complementation Test; D008957:Models, Genetic; D011993:Recombinant Fusion Proteins / Q000502:physiology; D013489:Suppression, Genetic
D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C086004:PriB protein, E coli; D011993:Recombinant Fusion Proteins; C459959:holD protein, E coli; C069995:PriC protein, E coli; D000251:Adenosine Triphosphatases; C506743:priA protein, E coli; D004265:DNA Helicases