2c98
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STRUCTURAL BASIS OF THE NUCLEOTIDE DRIVEN CONFORMATIONAL CHANGES IN THE AAA DOMAIN OF TRANSCRIPTION ACTIVATOR PSPF
OverviewOverview
Bacterial enhancer-binding proteins (EBP) activate transcription by, hydrolyzing ATP to restructure the sigma(54)-RNA polymerase-promoter, complex. We compare six high resolution structures (<2.1 A) of the AAA(+), domain of EBP phage shock protein F (PspF) including apo, AMPPNP, Mg(2+)-ATP, and ADP forms. These structures permit a description of the, atomic details underpinning the origins of the conformational changes, occurring during ATP hydrolysis. Conserved regions of PspF's AAA(+) domain, respond distinctively to nucleotide binding and hydrolysis, suggesting, functional roles during the hydrolysis cycle, which completely agree with, those derived from activities of PspF mutated at these positions. We, propose a putative atomic switch that is responsible for coupling, structural changes in the nucleotide-binding site to the repositioning of, the sigma(54)-interacting loops. Striking similarities in, nucleotide-specific conformational changes and atomic switch exist between, PspF and the large T antigen helicase, suggesting conservation in the, origin of those events amongst AAA(+) proteins.
About this StructureAbout this Structure
2C98 is a Single protein structure of sequence from Escherichia coli with ADP as ligand. Structure known Active Site: AC1. Full crystallographic information is available from OCA.
ReferenceReference
Structural basis of the nucleotide driven conformational changes in the AAA+ domain of transcription activator PspF., Rappas M, Schumacher J, Niwa H, Buck M, Zhang X, J Mol Biol. 2006 Mar 24;357(2):481-92. Epub 2006 Jan 13. PMID:16430918
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