The DNA replication priming protein, PriA, is required for homologous recombination and double-strand break repair.
The PriA protein, a component of the phiX174-type primosome, was previously shown to be essential for damage-inducible DNA replication in Escherichia coli, termed inducible stable DNA replication. Here, we show that priA::kan null mutants are defective in transductional and conjugational homologous recombination and are hypersensitive to mitomycin C and gamma rays, which cause double-strand breaks. The introduction of a plasmid carrying the priA300 allele, which encodes a mutant PriA protein capable of catalyzing the assembly of an active primosome but which is missing the n'-pas-dependent ATPase, helicase, and translocase activities associated with PriA, alleviates the defects of priA::kan mutants in homologous recombination, double-strand break repair, and inducible stable DNA replication. Furthermore, spa-47, which was isolated as a suppressor of the broth sensitivity of priA::kan mutants, suppresses the Rec- and mitomycin C sensitivity phenotypes of priA::kan mutants. The spa-47 suppressor mutation maps within or very near dnaC. These results suggest that PriA-dependent primosome assembly is crucial for both homologous recombination and double-strand break repair and support the proposal that these processes in E. coli involve extensive DNA replication.
Kogoma
T
T
Department of Cell Biology, University of New Mexico Health Sciences Center, Albuquerque 87131, USA.
Cadwell
G W
GW
Barnard
K G
KG
Asai
T
T
D001426:Bacterial Proteins / Q000378:metabolism; D004249:DNA Damage; D004260:DNA Repair; D004261:DNA Replication; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D004307:Dose-Response Relationship, Radiation; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins; D005090:Exodeoxyribonucleases / Q000378:metabolism; D009154:Mutation; D011995:Recombination, Genetic; D051716:Replication Protein A; D013489:Suppression, Genetic; D014466:Ultraviolet Rays / Q000009:adverse effects
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D051716:Replication Protein A; C489340:recF protein, E coli; C066218:recF protein, Bacteria; D005090:Exodeoxyribonucleases; C038225:recE protein, E coli