Building a replisome from interacting pieces: sliding clamp complexed to a peptide from DNA polymerase and a polymerase editing complex

Cell. 1999 Oct 15;99(2):155-66. doi: 10.1016/s0092-8674(00)81647-5.


We have solved the crystal structures of the bacteriophage RB69 sliding clamp, its complex with a peptide essential for DNA polymerase interactions, and the DNA polymerase complexed with primer-template DNA. The editing complex structure shows a partially melted duplex DNA exiting from the exonuclease domain at an unexpected angle and significant changes in the protein structure. The clamp complex shows the C-terminal 11 residues of polymerase bound in a hydrophobic pocket, and it allows docking of the editing and clamp structures together. The peptide binds to the sliding clamp at a position identical to that of a replication inhibitor peptide bound to PCNA, suggesting that the replication inhibitor protein p21CIP1 functions by competing with eukaryotic polymerases for the same binding pocket on the clamp.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Bacteriophages / genetics
  • Binding Sites
  • Crystallography, X-Ray
  • Cyclin-Dependent Kinase Inhibitor p21
  • Cyclins / metabolism
  • DNA Replication*
  • DNA, Viral / chemistry*
  • DNA, Viral / metabolism*
  • DNA-Directed DNA Polymerase / chemistry*
  • DNA-Directed DNA Polymerase / metabolism*
  • Models, Molecular
  • Molecular Sequence Data
  • Nucleic Acid Conformation
  • Nucleic Acid Denaturation
  • Proliferating Cell Nuclear Antigen / chemistry
  • Proliferating Cell Nuclear Antigen / metabolism
  • Protein Conformation
  • Protein Structure, Secondary
  • Templates, Genetic*


  • Cyclin-Dependent Kinase Inhibitor p21
  • Cyclins
  • DNA, Viral
  • Proliferating Cell Nuclear Antigen
  • DNA-Directed DNA Polymerase

Associated data

  • PDB/1B77
  • PDB/1B8H
  • PDB/1CLQ
  • PDB/1QE4