Binding to PCNA in Euryarchaeal DNA Replication requires two PIP motifs for DNA polymerase D and one PIP motif for DNA polymerase B

J Mol Biol. 2009 Nov 27;394(2):209-18. doi: 10.1016/j.jmb.2009.09.044. Epub 2009 Sep 23.


Replicative DNA polymerases possess a canonical C-terminal proliferating cell nuclear antigen (PCNA)-binding motif termed the PCNA-interacting protein (PIP) box. We investigated the role of the PIP box on the functional interactions of the two DNA polymerases, PabPol B (family B) and PabPol D (family D), from the hyperthermophilic euryarchaeon Pyrococcus abyssi, with its cognate PCNA. The PIP box was essential for interactions of PabPol B with PCNA, as shown by surface plasmon resonance and primer extension studies. In contrast, binding of PabPol D to PCNA was affected only partially by removing the PIP motif. We identified a second palindromic PIP box motif at the N-terminus of the large subunit of PabPol D that was required for the interactions of PabPol D with PCNA. Thus, two PIP motifs were needed for PabPol D for binding to PabPCNA. Moreover, the C-terminus of PabPCNA was essential for stimulation of PabPol D activity but not for stimulation of PabPol B activity. Neither DNA polymerase interacted with the PabPCNA interdomain connecting loop. Our data suggest that distinct processes are involved in PabPol D and PabPol B binding to PCNA, raising the possibility that Archaea require two mechanisms for recruiting replicative DNA polymerases at the replication fork.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Motifs
  • Amino Acid Sequence
  • DNA Polymerase II / genetics
  • DNA Polymerase II / metabolism*
  • DNA Replication*
  • DNA-Directed DNA Polymerase / genetics
  • DNA-Directed DNA Polymerase / metabolism*
  • Molecular Sequence Data
  • Mutation
  • Proliferating Cell Nuclear Antigen / metabolism*
  • Pyrococcus abyssi / genetics
  • Pyrococcus abyssi / metabolism*


  • Proliferating Cell Nuclear Antigen
  • DNA Polymerase II
  • DNA-Directed DNA Polymerase