Enzymatic switching for efficient and accurate translesion DNA replication

Nucleic Acids Res. 2004 Aug 27;32(15):4665-75. doi: 10.1093/nar/gkh777. Print 2004.


When cyclobutane pyrimidine dimers stall DNA replication by DNA polymerase (Pol) delta or epsilon, a switch occurs to allow translesion synthesis by DNA polymerase eta, followed by another switch that allows normal replication to resume. In the present study, we investigate these switches using Saccharomyces cerevisiae Pol delta, Pol epsilon and Pol eta and a series of matched and mismatched primer templates that mimic each incorporation needed to completely bypass a cis-syn thymine-thymine (TT) dimer. We report a complementary pattern of substrate use indicating that enzymatic switching involving localized translesion synthesis by Pol eta and mismatch excision and polymerization by a major replicative polymerase can account for the efficient and accurate dimer bypass known to suppress sunlight-induced mutagenesis and skin cancer.

Publication types

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

MeSH terms

  • Base Pair Mismatch
  • DNA Damage*
  • DNA Polymerase II / metabolism
  • DNA Polymerase III / metabolism
  • DNA Replication*
  • DNA-Directed DNA Polymerase / metabolism*
  • Exodeoxyribonucleases / metabolism
  • Models, Genetic
  • Pyrimidine Dimers / metabolism
  • Saccharomyces cerevisiae / enzymology


  • Pyrimidine Dimers
  • DNA Polymerase II
  • DNA Polymerase III
  • DNA-Directed DNA Polymerase
  • Rad30 protein
  • Exodeoxyribonucleases