The active form of DNA polymerase V is UmuD'(2)C-RecA-ATP

Nature. 2009 Jul 16;460(7253):359-63. doi: 10.1038/nature08178.


DNA-damage-induced SOS mutations arise when Escherichia coli DNA polymerase (pol) V, activated by a RecA nucleoprotein filament (RecA*), catalyses translesion DNA synthesis. Here we address two longstanding enigmatic aspects of SOS mutagenesis, the molecular composition of mutagenically active pol V and the role of RecA*. We show that RecA* transfers a single RecA-ATP stoichiometrically from its DNA 3'-end to free pol V (UmuD'(2)C) to form an active mutasome (pol V Mut) with the composition UmuD'(2)C-RecA-ATP. Pol V Mut catalyses TLS in the absence of RecA* and deactivates rapidly upon dissociation from DNA. Deactivation occurs more slowly in the absence of DNA synthesis, while retaining RecA-ATP in the complex. Reactivation of pol V Mut is triggered by replacement of RecA-ATP from RecA*. Thus, the principal role of RecA* in SOS mutagenesis is to transfer RecA-ATP to pol V, and thus generate active mutasomal complex for translesion synthesis.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, N.I.H., Intramural

MeSH terms

  • Adenosine Triphosphate / metabolism*
  • DNA Replication
  • DNA, Single-Stranded / metabolism
  • DNA-Directed DNA Polymerase / chemistry*
  • DNA-Directed DNA Polymerase / genetics
  • DNA-Directed DNA Polymerase / metabolism*
  • Enzyme Activation
  • Escherichia coli / enzymology*
  • Escherichia coli Proteins / chemistry*
  • Escherichia coli Proteins / genetics
  • Escherichia coli Proteins / metabolism*
  • Models, Biological
  • Molecular Weight
  • Multienzyme Complexes / chemistry
  • Multienzyme Complexes / metabolism
  • Rec A Recombinases / metabolism*
  • SOS Response, Genetics
  • Transcriptional Activation


  • DNA, Single-Stranded
  • Escherichia coli Proteins
  • Multienzyme Complexes
  • Adenosine Triphosphate
  • UmuC protein, E coli
  • Rec A Recombinases
  • DNA polymerase V, E coli
  • DNA-Directed DNA Polymerase
  • UmuD protein, E coli