1njf

Publication Abstract from PubMed

Sliding 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.