Archaeal eukaryote-like Orc1/Cdc6 initiators physically interact with DNA polymerase B1 and regulate its functions

Proc Natl Acad Sci U S A. 2009 May 12;106(19):7792-7. doi: 10.1073/pnas.0813056106. Epub 2009 Apr 29.


Archaeal DNA replication machinery represents a core version of that found in eukaryotes. However, the proteins essential for the coordination of origin selection and the functioning of DNA polymerase have not yet been characterized in archaea, and they are still being investigated in eukaryotes. In the current study, the Orc1/Cdc6 (SsoCdc6) proteins from the crenarchaeon Sulfolobus solfataricus were found to physically interact with its DNA polymerase B1 (SsoPolB1). These SsoCdc6 proteins stimulated the DNA-binding ability of SsoPolB1 and differentially regulated both its polymerase and nuclease activities. Furthermore, the proteins also mutually regulated their interactions with SsoPolB1. In addition, SsoPolB1c467, a nuclease domain-deleted mutant of SsoPolB1 defective in DNA binding, retains the ability to physically interact with SsoCdc6 proteins. Its DNA polymerase activity could be stimulated by these proteins. We report on a linkage between the initiator protein Orc1/Cdc6 and DNA polymerase in the archaeon. Our present and previous findings indicate that archaeal Orc1/Cdc6 proteins could potentially play critical roles in the coordination of origin selection and cell-cycle control of replication.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Archaea
  • Archaeal Proteins / metabolism
  • Base Sequence
  • Cell Cycle Proteins / metabolism*
  • Cloning, Molecular
  • DNA Polymerase beta / metabolism*
  • DNA Replication
  • DNA-Directed DNA Polymerase / metabolism
  • Gene Expression Regulation, Enzymologic*
  • Molecular Sequence Data
  • Oligonucleotides / chemistry
  • Origin Recognition Complex / physiology*
  • Sulfolobus solfataricus / metabolism
  • Two-Hybrid System Techniques


  • Archaeal Proteins
  • Cell Cycle Proteins
  • Oligonucleotides
  • Origin Recognition Complex
  • DNA Polymerase beta
  • DNA-Directed DNA Polymerase