Yeast DNA polymerase eta utilizes an induced-fit mechanism of nucleotide incorporation

Cell. 2001 Dec 28;107(7):917-27. doi: 10.1016/s0092-8674(01)00613-4.

Abstract

DNA polymerase eta (Poleta) is unique among eukaryotic DNA polymerases in its proficient ability to replicate through distorting DNA lesions, and Poleta synthesizes DNA with a low fidelity. Here, we use pre-steady-state kinetics to investigate the mechanism of nucleotide incorporation by Poleta and show that it utilizes an induced-fit mechanism to selectively incorporate the correct nucleotide. Poleta discriminates poorly between the correct and incorrect nucleotide at both the initial nucleotide binding step and at the subsequent induced-fit conformational change step, which precedes the chemical step of phosphodiester bond formation. This property enables Poleta to bypass lesions with distorted DNA geometries, and it bestows upon the enzyme a low fidelity.

Publication types

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

MeSH terms

  • DNA / genetics
  • DNA / metabolism*
  • DNA Repair*
  • DNA-Directed DNA Polymerase / genetics
  • DNA-Directed DNA Polymerase / metabolism*
  • Kinetics
  • Nucleotides / genetics
  • Nucleotides / metabolism*
  • Saccharomyces cerevisiae / enzymology*
  • Saccharomyces cerevisiae / genetics*
  • Substrate Specificity

Substances

  • Nucleotides
  • DNA
  • DNA-Directed DNA Polymerase
  • Rad30 protein