Crystal structure of the processivity clamp loader gamma (gamma) complex of E. coli DNA polymerase III.
The gamma complex, an AAA+ ATPase, is the bacterial homolog of eukaryotic replication factor C (RFC) that loads the sliding clamp (beta, homologous to PCNA) onto DNA. The 2.7/3.0 A crystal structure of gamma complex reveals a pentameric arrangement of subunits, with stoichiometry delta':gamma(3):delta. The C-terminal domains of the subunits form a circular collar that supports an asymmetric arrangement of the N-terminal ATP binding domains of the gamma motor and the structurally related domains of the delta' stator and the delta wrench. The structure suggests a mechanism by which the gamma complex switches between a closed state, in which the beta-interacting element of delta is hidden by delta', and an open form similar to the crystal structure, in which delta is free to bind to beta.
Jeruzalmi
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D
Howard Hughes Medical Institute, The Rockefeller University, 1230 York Avenue, New York, NY 10021, USA.
O'Donnell
M
M
Kuriyan
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J
D001665:Binding Sites; D018360:Crystallography, X-Ray; D000074002:DNA Polymerase gamma; D004259:DNA-Directed DNA Polymerase / Q000737:chemistry* / Q000378:metabolism; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D046911:Macromolecular Substances; D008958:Models, Molecular; D011485:Protein Binding; D011487:Protein Conformation; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary
D046911:Macromolecular Substances; D000074002:DNA Polymerase gamma; D004259:DNA-Directed DNA Polymerase