Roles of DNA polymerases V and II in SOS-induced error-prone and error-free repair in Escherichia coli.
DNA polymerase V, composed of a heterotrimer of the DNA damage-inducible UmuC and UmuD(2)(') proteins, working in conjunction with RecA, single-stranded DNA (ssDNA)-binding protein (SSB), beta sliding clamp, and gamma clamp loading complex, are responsible for most SOS lesion-targeted mutations in Escherichia coli, by catalyzing translesion synthesis (TLS). DNA polymerase II, the product of the damage-inducible polB (dinA ) gene plays a pivotal role in replication-restart, a process that bypasses DNA damage in an error-free manner. Replication-restart takes place almost immediately after the DNA is damaged (approximately 2 min post-UV irradiation), whereas TLS occurs after pol V is induced approximately 50 min later. We discuss recent data for pol V-catalyzed TLS and pol II-catalyzed replication-restart. Specific roles during TLS for pol V and each of its accessory factors have been recently determined. Although the precise molecular mechanism of pol II-dependent replication-restart remains to be elucidated, it has recently been shown to operate in conjunction with RecFOR and PriA proteins.
Pham
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Department of Biological Sciences, Hedco Molecular Biology Laboratories, University of Southern California, Los Angeles, CA 90089-1340, USA.
Rangarajan
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Woodgate
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R
Goodman
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MF
D002384:Catalysis; D004257:DNA Polymerase II / Q000378:metabolism / Q000502:physiology*; D004260:DNA Repair; D004269:DNA, Bacterial / Q000096:biosynthesis; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism / Q000502:physiology*; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics; D029968:Escherichia coli Proteins; D008957:Models, Genetic; D016296:Mutagenesis; D011938:Rec A Recombinases / Q000378:metabolism; D013014:SOS Response, Genetics
D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D011938:Rec A Recombinases; D004257:DNA Polymerase II; C120926:DNA polymerase V, E coli; D004259:DNA-Directed DNA Polymerase