In vivo reconstitution of Saccharomyces cerevisiae DNA polymerase epsilon in insect cells. Purification and characterization

J Biol Chem. 2002 Mar 8;277(10):7889-96. doi: 10.1074/jbc.M108546200. Epub 2001 Dec 26.


DNA polymerase epsilon (pol epsilon) is a multiple subunit complex consisting of at least four proteins, including catalytic Pol2p, Dpb2p, Dpb3p, and Dpb4p. Pol epsilon has been shown to play essential roles in chromosomal DNA replication. Here, we report reconstitution of the yeast pol epsilon complex, which was expressed and purified from baculovirus-infected insect cells. During the purification, we were able to resolve the pol epsilon complex and truncated Pol2p (140 kDa), as was observed initially with the pol epsilon purified from yeast. Biochemical characterization of subunit stoichiometry, salt sensitivity, processivity, and stimulation by proliferating cell nuclear antigen indicates that the reconstituted pol epsilon is functionally identical to native pol epsilon purified from yeast and is therefore useful for biochemical characterization of the interactions of pol epsilon with other replication, recombination, and repair proteins. Identification and characterization of a proliferating cell nuclear antigen consensus interaction domain on Pol2p indicates that the motif is dispensable for DNA replication but is important for methyl methanesulfonate damage-induced DNA repair. Analysis of the putative zinc finger domain of Pol2p for zinc binding capacity demonstrates that it binds zinc. Mutations of the conserved cysteines in the putative zinc finger domain reduced zinc binding, indicating that cysteine ligands are directly involved in binding zinc.

Publication types

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

MeSH terms

  • Amino Acid Motifs
  • Amino Acid Sequence
  • Animals
  • Baculoviridae / metabolism
  • Cell Division
  • Cell Line
  • Cell Survival
  • Cysteine / chemistry
  • DNA / metabolism
  • DNA Polymerase II / chemistry
  • DNA Polymerase II / metabolism*
  • DNA Repair
  • Dose-Response Relationship, Drug
  • Insecta
  • Molecular Sequence Data
  • Mutation
  • Proliferating Cell Nuclear Antigen / metabolism
  • Protein Binding
  • Protein Structure, Tertiary
  • Recombinant Fusion Proteins / metabolism
  • Saccharomyces cerevisiae / enzymology*
  • Sequence Homology, Amino Acid
  • Time Factors
  • Zinc / metabolism
  • Zinc Fingers


  • Proliferating Cell Nuclear Antigen
  • Recombinant Fusion Proteins
  • DNA
  • DNA Polymerase II
  • Zinc
  • Cysteine