title: Clamp loader ATPases and the evolution of DNA replication machinery.
abstract: Clamp loaders are pentameric ATPases of the AAA+ family that operate to ensure processive DNA replication. They do so by loading onto DNA the ring-shaped sliding clamps that tether the polymerase to the DNA. Structural and biochemical analysis of clamp loaders has shown how, despite differences in composition across different branches of life, all clamp loaders undergo the same concerted conformational transformations, which generate a binding surface for the open clamp and an internal spiral chamber into which the DNA at the replication fork can slide, triggering ATP hydrolysis, release of the clamp loader, and closure of the clamp round the DNA. We review here the current understanding of the clamp loader mechanism and discuss the implications of the differences between clamp loaders from the different branches of life.
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA. bkelch@berkeley.edu
authors.forename: Brian A
authors.initials: BA
authors.lastname: Kelch
authors.forename: Debora L
authors.initials: DL
authors.lastname: Makino
authors.forename: Mike
authors.initials: M
authors.lastname: O'Donnell
authors.forename: John
authors.initials: J
authors.lastname: Kuriyan
mesh_terms: D000251:Adenosine Triphosphatases / Q000737:chemistry / Q000378:metabolism*; D001419:Bacteria / Q000737:chemistry / Q000145:classification / Q000201:enzymology / Q000235:genetics; D017122:Bacteriophage T4 / Q000737:chemistry / Q000145:classification / Q000201:enzymology / Q000235:genetics; D004261:DNA Replication; D056890:Eukaryota / Q000737:chemistry / Q000145:classification / Q000201:enzymology / Q000235:genetics; D019143:Evolution, Molecular; D006868:Hydrolysis; D008958:Models, Molecular; D010802:Phylogeny; D017434:Protein Structure, Tertiary
chemical_list: D000251:Adenosine Triphosphatases