1e0k
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GP4D HELICASE FROM PHAGE T7
OverviewOverview
We have determined the crystal structure of an active, hexameric fragment, of the gene 4 helicase from bacteriophage T7. The structure reveals how, subunit contacts stabilize the hexamer. Deviation from expected six-fold, symmetry of the hexamer indicates that the structure is of an intermediate, on the catalytic pathway. The structural consequences of the asymmetry, suggest a "binding change" mechanism to explain how cooperative binding, and hydrolysis of nucleotides are coupled to conformational changes in the, ring that most likely accompany duplex unwinding. The structure of a, complex with a nonhydrolyzable ATP analog provides additional evidence for, this hypothesis, with only four of the six possible nucleotide binding, sites being occupied in this conformation of the hexamer. This model, suggests a mechanism for DNA translocation.
About this StructureAbout this Structure
1E0K is a Single protein structure of sequence from Bacteriophage t7. Full crystallographic information is available from OCA.
ReferenceReference
Crystal structure of T7 gene 4 ring helicase indicates a mechanism for sequential hydrolysis of nucleotides., Singleton MR, Sawaya MR, Ellenberger T, Wigley DB, Cell. 2000 Jun 9;101(6):589-600. PMID:10892646
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