Motors and switches: AAA+ machines within the replisome

Nat Rev Mol Cell Biol. 2002 Nov;3(11):826-35. doi: 10.1038/nrm949.


Clamp loaders are required to load the ring-shaped clamps that tether replicative DNA polymerases onto DNA. Recently solved crystal structures, along with a series of biochemical studies, have provided a detailed understanding of the clamp loading reaction. In particular, studies of the Escherichia coli clamp loader--an AAA+ machine--have provided insights into the architecture of clamp loaders from eukaryotes, bacteriophage T4 and archaea. Other AAA+ proteins are also involved in the initiation of DNA replication, and studies of the E. coli clamp loader indicate mechanisms by which these proteins might function.

Publication types

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

MeSH terms

  • Archaea / physiology
  • Bacterial Proteins / physiology
  • Bacteriophages / physiology
  • DNA Replication / physiology*
  • DNA-Binding Proteins / chemistry
  • DNA-Binding Proteins / physiology*
  • DNA-Directed DNA Polymerase / chemistry
  • DNA-Directed DNA Polymerase / physiology
  • Escherichia coli / physiology
  • Eukaryotic Cells / physiology
  • Humans
  • Molecular Motor Proteins / physiology*
  • Origin Recognition Complex
  • Protein Structure, Tertiary


  • Bacterial Proteins
  • DNA-Binding Proteins
  • DnaA protein, Bacteria
  • Molecular Motor Proteins
  • Origin Recognition Complex
  • DNA-Directed DNA Polymerase