Direct interaction between mammalian DNA polymerase beta and proliferating cell nuclear antigen

J Biol Chem. 2002 Aug 23;277(34):31115-23. doi: 10.1074/jbc.M201497200. Epub 2002 Jun 12.


Proliferating cell nuclear antigen (PCNA) plays an essential role in nucleic acid metabolism as a component of the DNA replication and DNA repair machinery. As such, PCNA interacts with many proteins that have a sequence motif termed the PCNA interacting motif (PIM) and also with proteins lacking a PIM. Three regions in human and rat DNA polymerases beta (beta-pol) that resemble the consensus PIM were identified, and we show here that beta-polymerase and PCNA can form a complex both in vitro and in vivo. Immunoprecipitation experiments, yeast two-hybrid analysis, and overlay binding assays were used to examine the interaction between the two proteins. Competition experiments with synthetic PIM-containing peptides suggested the importance of a PIM in the interaction, and studies of a beta-polymerase PIM mutant, H222A/F223A, demonstrated that this alteration blocked the interaction with PCNA. The results indicate that at least one of the PIM-like sequences in beta-polymerase appears to be a functional PIM and was required in the interaction between beta-polymerase and PCNA.

Publication types

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

MeSH terms

  • Amino Acid Motifs
  • Amino Acid Sequence
  • Animals
  • Binding Sites
  • Cell Line
  • DNA / metabolism
  • DNA Polymerase beta / chemistry
  • DNA Polymerase beta / metabolism*
  • Mice
  • Molecular Sequence Data
  • Precipitin Tests
  • Proliferating Cell Nuclear Antigen / chemistry
  • Proliferating Cell Nuclear Antigen / metabolism*
  • Structure-Activity Relationship
  • Two-Hybrid System Techniques


  • Proliferating Cell Nuclear Antigen
  • DNA
  • DNA Polymerase beta