Requirement of Watson-Crick hydrogen bonding for DNA synthesis by yeast DNA polymerase eta

Mol Cell Biol. 2003 Jul;23(14):5107-12. doi: 10.1128/MCB.23.14.5107-5112.2003.


Classical high-fidelity DNA polymerases discriminate between the correct and incorrect nucleotides by using geometric constraints imposed by the tight fit of the active site with the incipient base pair. Consequently, Watson-Crick (W-C) hydrogen bonding between the bases is not required for the efficiency and accuracy of DNA synthesis by these polymerases. DNA polymerase eta (Poleta) is a low-fidelity enzyme able to replicate through DNA lesions. Using difluorotoluene, a nonpolar isosteric analog of thymine unable to form W-C hydrogen bonds with adenine, we found that the efficiency and accuracy of nucleotide incorporation by Poleta are severely impaired. From these observations, we suggest that W-C hydrogen bonding is required for DNA synthesis by Poleta; in this regard, Poleta differs strikingly from classical high-fidelity DNA polymerases.

Publication types

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

MeSH terms

  • DNA / biosynthesis*
  • DNA / chemistry
  • DNA-Directed DNA Polymerase / chemistry
  • DNA-Directed DNA Polymerase / metabolism*
  • Fungal Proteins / genetics
  • Fungal Proteins / metabolism
  • Hydrogen Bonding*
  • Kinetics
  • Nucleotides / chemistry
  • Nucleotides / metabolism
  • Toluene / analogs & derivatives*
  • Toluene / chemistry
  • Yeasts / genetics
  • Yeasts / metabolism


  • Fungal Proteins
  • Nucleotides
  • Toluene
  • difluorotoluene
  • DNA
  • DNA-Directed DNA Polymerase
  • Rad30 protein