Roles of DNA polymerases V and II in SOS-induced error-prone and error-free repair in Escherichia coli

doi:10.1073/pnas.111007198

Roles of DNA polymerases V and II in SOS-induced error-prone and error-free repair in Escherichia coli

^*Departments of Biological Sciences and Chemistry, Hedco Molecular Biology Laboratories, University of Southern California, Los Angeles, CA 90089-1340; and ^†Section on DNA Replication, Repair and Mutagenesis, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-2725

Abstract

DNA polymerase V, composed of a heterotrimer of the DNA damage-inducible UmuC and UmuD $\text{[math]}$ proteins, working in conjunction with RecA, single-stranded DNA (ssDNA)-binding protein (SSB), β sliding clamp, and γ 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 (≈2 min post-UV irradiation), whereas TLS occurs after pol V is induced ≈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.

Footnotes

↵ ‡ To whom reprint requests should be addressed. E-mail: mgoodman{at}mizar.usc.edu.
This paper results from the National Academy of Sciences colloquium, “Links Between Recombination and Replication: Vital Roles of Recombination,” held November 10–12, 2000, in Irvine, CA.
↵ § A locomotive cowcatcher is a pointed device attached to the front of locomotives designed to push obstacles off the track ahead of an advancing train.
Abbreviations:

TLS,

translesion synthesis;

p/t,

primer-template;

ssDNA,

single-stranded DNA;

SSB,

ssDNA-binding protein