DNA polymerase V and RecA protein, a minimal mutasome

Mol Cell. 2005 Feb 18;17(4):561-72. doi: 10.1016/j.molcel.2005.01.006.


A hallmark of the Escherichia coli SOS response is the large increase in mutations caused by translesion synthesis (TLS). TLS requires DNA polymerase V (UmuD'2C) and RecA. Here, we show that pol V and RecA interact by two distinct mechanisms. First, pol V binds to RecA in the absence of DNA and ATP and second, through its UmuD' subunit, requiring DNA and ATP without ATP hydrolysis. TLS occurs in the absence of a RecA nucleoprotein filament but is inhibited in its presence. Therefore, a RecA nucleoprotein filament is unlikely to be required for SOS mutagenesis. Pol V activity is severely diminished in the absence of RecA or in the presence of RecA1730, a mutant defective for pol V mutagenesis in vivo. Pol V activity is strongly enhanced with RecA mutants constitutive for mutagenesis in vivo, suggesting that RecA is an obligate accessory factor that activates pol V for SOS mutagenesis.

Publication types

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

MeSH terms

  • Adenosine Triphosphate / metabolism
  • DNA Damage*
  • DNA Replication / physiology*
  • DNA, Bacterial / genetics
  • DNA, Bacterial / metabolism
  • DNA-Directed DNA Polymerase / metabolism*
  • Escherichia coli / enzymology
  • Escherichia coli / genetics*
  • Escherichia coli Proteins / metabolism
  • Mutagenesis
  • Mutation / genetics*
  • Rec A Recombinases / metabolism*


  • DNA, Bacterial
  • Escherichia coli Proteins
  • Adenosine Triphosphate
  • Rec A Recombinases
  • DNA polymerase V, E coli
  • DNA-Directed DNA Polymerase
  • UmuD protein, E coli