RecFOR proteins are essential for Pol V-mediated translesion synthesis and mutagenesis.
When the replication fork moves through the template DNA containing lesions, daughter-strand gaps are formed opposite lesion sites. These gaps are subsequently filled-in either by translesion synthesis (TLS) or by homologous recombination. RecA filaments formed within these gaps are key intermediates for both of the gap-filling pathways. For instance, Pol V, the major lesion bypass polymerase in Escherichia coli, requires a functional interaction with the tip of the RecA filament. Here, we show that all three recombination mediator proteins RecFOR are needed to build a functionally competent RecA filament that supports efficient Pol V-mediated TLS in the presence of ssDNA-binding protein (SSB). A positive contribution of RecF protein to Pol V lesion bypass is demonstrated. When Pol III and Pol V are both present, Pol III imparts a negative effect on Pol V-mediated lesion bypass that is counteracted by the combined action of RecFOR and SSB. Mutations in recF, recO or recR gene abolish induced mutagenesis in E. coli.
Fujii
Shingo
S
Genome Instability and Carcinogenesis, CNRS, FRE 2931, 31 chemin Joseph Aiguier, 13402 Marseille cedex 20, France.
Isogawa
Asako
A
Fuchs
Robert P
RP
D004258:DNA Polymerase III / Q000378:metabolism; D017931:DNA Primers / Q000378:metabolism; D004269:DNA, Bacterial / Q000096:biosynthesis*; D004268:DNA-Binding Proteins / Q000378:metabolism; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism*; D004926:Escherichia coli / Q000378:metabolism* / Q000528:radiation effects; D029968:Escherichia coli Proteins / Q000378:metabolism*; D007700:Kinetics; D008957:Models, Genetic; D016296:Mutagenesis; D009154:Mutation / Q000235:genetics; D011740:Pyrimidine Dimers / Q000378:metabolism; D011938:Rec A Recombinases / Q000378:metabolism; D014466:Ultraviolet Rays
D017931:DNA Primers; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D011740:Pyrimidine Dimers; C081006:RecO protein, E coli; C489318:RecR protein, E coli; C489340:recF protein, E coli; C059224:cyclobutyldithymidine dimers; D011938:Rec A Recombinases; D004258:DNA Polymerase III; C120926:DNA polymerase V, E coli; D004259:DNA-Directed DNA Polymerase