2c98: Difference between revisions
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==Overview== | ==Overview== | ||
Bacterial enhancer-binding proteins (EBP) activate transcription by | 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 Structure== | ==About this Structure== | ||
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[[Category: two-component regulatory system]] | [[Category: two-component regulatory system]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:46:26 2008'' | ||
Revision as of 17:46, 21 February 2008
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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 as ligand. Known structural/functional Site: . 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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