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

Proc Natl Acad Sci U S A. 2001 Jul 17;98(15):8350-4. doi: 10.1073/pnas.111007198.


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.

Publication types

  • Research Support, U.S. Gov't, P.H.S.
  • Review

MeSH terms

  • Catalysis
  • DNA Polymerase II / metabolism
  • DNA Polymerase II / physiology*
  • DNA Repair*
  • DNA, Bacterial / biosynthesis
  • DNA-Directed DNA Polymerase / metabolism
  • DNA-Directed DNA Polymerase / physiology*
  • Escherichia coli / enzymology
  • Escherichia coli / genetics
  • Escherichia coli Proteins
  • Models, Genetic
  • Mutagenesis
  • Rec A Recombinases / metabolism
  • SOS Response, Genetics*


  • DNA, Bacterial
  • Escherichia coli Proteins
  • Rec A Recombinases
  • DNA Polymerase II
  • DNA polymerase V, E coli
  • DNA-Directed DNA Polymerase