Evidence for interplay among yeast replicative DNA polymerases alpha, delta and epsilon from studies of exonuclease and polymerase active site mutations

Youri I Pavlov, Satoko Maki, Hisaji Maki, Thomas A. Kunkel

Research output: Contribution to journalArticle

36 Scopus citations

Abstract

Background: DNA polymerase E (Pol E) is essential for S-phase replication, DNA damage repair and checkpoint control in yeast. A pol2-Y831A mutation leading to a tyrosine to alanine change in the Pol E active site does not cause growth defects and confers a mutator phenotype that is normally subtle but strong in a mismatch repair-deficient strain. Here we investigate the mechanism responsible for the mutator effect. Results: Purified four-subunit Y831A Pol E turns over more deoxynucleoside triphosphates to deoxynucleoside monophosphates than does wild-type Pol E, suggesting altered coordination between the polymerase and exonuclease active sites. The pol2-Y831A mutation suppresses the mutator effect of the pol2-4 mutation in the exonuclease active site that abolishes proofreading by Pol E, as measured in haploid strain with the pol2-Y831A,4 double mutation. Analysis of mutation rates in diploid strains reveals that the pol2-Y831A allele is recessive to pol2-4. In addition, the mutation rates of strains with the pol2-4 mutation in combination with active site mutator mutations in Pol δ and Pol α suggest that Pol E may proofread certain errors made by Pol α and Pol δ during replication in vivo. Conclusions: Our data suggest that Y831A replacement in Pol E reduces replication fidelity and its participation in chromosomal replication, but without eliminating an additional function that is essential for viability. This suggests that other polymerases can substitute for certain functions of polymerase E.

Original languageEnglish (US)
Article number11
JournalBMC Biology
Volume2
DOIs
Publication statusPublished - May 26 2004

    Fingerprint

ASJC Scopus subject areas

  • Biotechnology
  • Structural Biology
  • Ecology, Evolution, Behavior and Systematics
  • Physiology
  • Biochemistry, Genetics and Molecular Biology(all)
  • Agricultural and Biological Sciences(all)
  • Plant Science
  • Developmental Biology
  • Cell Biology

Cite this