1h3d: Difference between revisions
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==Overview== | ==Overview== | ||
ATP-phosphoribosyltransferase (ATP-PRT), the first enzyme of the histidine | ATP-phosphoribosyltransferase (ATP-PRT), the first enzyme of the histidine pathway, is a complex allosterically regulated enzyme, which controls the flow of intermediates through this biosynthetic pathway. The crystal structures of Escherichia coli ATP-PRT have been solved in complex with the inhibitor AMP at 2.7A and with product PR-ATP at 2.9A (the ribosyl-triphosphate could not be resolved). On the basis of binding of AMP and PR-ATP and comparison with type I PRTs, the PRPP and parts of the ATP-binding site are identified. These structures clearly identify the AMP as binding in the 5-phosphoribosyl-alpha-1-pyrophosphate (PRPP)-binding site, with the adenosine ring occupying the ATP-binding site. Comparison with the recently solved Mycobacterium tuberculosis ATP-PRT structures indicates that histidine is solely responsible for the large conformational changes observed between the hexameric forms of the enzyme. The role of oligomerisation in inhibition and the structural basis for the synergistic inhibition by histidine and AMP are discussed. | ||
==About this Structure== | ==About this Structure== | ||
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[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Coggins, J | [[Category: Coggins, J R.]] | ||
[[Category: Lapthorn, A | [[Category: Lapthorn, A J.]] | ||
[[Category: Lohkamp, B.]] | [[Category: Lohkamp, B.]] | ||
[[Category: Mcdermott, G.]] | [[Category: Mcdermott, G.]] | ||
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[[Category: transferase]] | [[Category: transferase]] | ||
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Revision as of 13:57, 21 February 2008
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STRUCTURE OF THE E.COLI ATP-PHOSPHORIBOSYLTRANSFERASE
OverviewOverview
ATP-phosphoribosyltransferase (ATP-PRT), the first enzyme of the histidine pathway, is a complex allosterically regulated enzyme, which controls the flow of intermediates through this biosynthetic pathway. The crystal structures of Escherichia coli ATP-PRT have been solved in complex with the inhibitor AMP at 2.7A and with product PR-ATP at 2.9A (the ribosyl-triphosphate could not be resolved). On the basis of binding of AMP and PR-ATP and comparison with type I PRTs, the PRPP and parts of the ATP-binding site are identified. These structures clearly identify the AMP as binding in the 5-phosphoribosyl-alpha-1-pyrophosphate (PRPP)-binding site, with the adenosine ring occupying the ATP-binding site. Comparison with the recently solved Mycobacterium tuberculosis ATP-PRT structures indicates that histidine is solely responsible for the large conformational changes observed between the hexameric forms of the enzyme. The role of oligomerisation in inhibition and the structural basis for the synergistic inhibition by histidine and AMP are discussed.
About this StructureAbout this Structure
1H3D is a Single protein structure of sequence from Escherichia coli with and as ligands. Active as ATP phosphoribosyltransferase, with EC number 2.4.2.17 Known structural/functional Site: . Full crystallographic information is available from OCA.
ReferenceReference
The structure of Escherichia coli ATP-phosphoribosyltransferase: identification of substrate binding sites and mode of AMP inhibition., Lohkamp B, McDermott G, Campbell SA, Coggins JR, Lapthorn AJ, J Mol Biol. 2004 Feb 6;336(1):131-44. PMID:14741209
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