1njg
Nucleotide-free form of an Isolated E. coli Clamp Loader Gamma Subunit
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| , resolution 2.20Å | |||||||
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| Ligands: | and | ||||||
| Gene: | DnaX (Escherichia coli) | ||||||
| Activity: | DNA-directed DNA polymerase, with EC number 2.7.7.7 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
OverviewOverview
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.
About this StructureAbout this Structure
1NJG is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
ReferenceReference
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
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