1njg
Nucleotide-free form of an Isolated E. coli Clamp Loader Gamma SubunitNucleotide-free form of an Isolated E. coli Clamp Loader Gamma Subunit
Structural highlights
FunctionDPO3X_ECOLI DNA polymerase III is a complex, multichain enzyme responsible for most of the replicative synthesis in bacteria. This DNA polymerase also exhibits 3' to 5' exonuclease activity. Isoform tau: serves as a scaffold to help in the dimerization of the core complex. Isoform gamma: seems to interact with the delta subunit. to transfer the beta subunit on the DNA. Evolutionary Conservation![]() Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedSliding clamps are loaded onto DNA by ATP-driven clamp loader complexes. The structure of the E. coli clamp loader in a nucleotide-free state has been determined previously. We now report crystal structures of a truncated form of the isolated gamma-ATPase subunit, gamma(1-243), of the E. coli clamp loader, in nucleotide-free and bound forms. The gamma subunit adopts a defined conformation when empty, in which the nucleotide binding site is blocked. The binding of either ATPgammaS or ADP, which are shown to bind with equal affinity to gamma(1-243), induces a change in the relative orientation of the two domains such that nucleotides can be accommodated. This change would break one of the gamma:gamma interfaces seen in the empty clamp loader complex, and may represent one step in the activation process. Nucleotide-induced conformational changes in an isolated Escherichia coli DNA polymerase III clamp loader subunit.,Podobnik M, Weitze TF, O'Donnell M, Kuriyan J Structure. 2003 Mar;11(3):253-63. PMID:12623013[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences |
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