1esm

STRUCTURAL BASIS FOR THE FEEDBACK REGULATION OF ESCHERICHIA COLI PANTOTHENATE KINASE BY COENZYME A

spinqualitylabelsall models 1esm, resolution 2.50Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1esm is a 4 chain structure with sequence from Escherichia coli. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.5Å Ligands: COA, MSE Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function COAA_ECOLI Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed Pantothenate kinase (PanK) is a key regulatory enzyme in the coenzyme A (CoA) biosynthetic pathway and catalyzes the phosphorylation of pantothenic acid to form phosphopantothenate. CoA is a feedback inhibitor of PanK activity by competitive binding to the ATP site. The structures of the Escherichia coli enzyme, in complex with a nonhydrolyzable analogue of ATP, 5'-adenylimido-diphosphate (AMPPNP), or with CoA, were determined at 2.6 and 2.5 A, respectively. Both structures show that two dimers occupy an asymmetric unit; each subunit has a alpha/beta mononucleotide-binding fold with an extensive antiparallel coiled coil formed by two long helices along the dimerization interface. The two ligands, AMPPNP and CoA, associate with PanK in very different ways, but their phosphate binding sites overlap, explaining the kinetic competition between CoA and ATP. Residues Asp(127), His(177), and Arg(243) are proposed to be involved in catalysis, based on modeling of the pentacoordinate transition state. The more potent inhibition by CoA, compared with the CoA thioesters, is explained by a tight interaction of the CoA thiol group with the side chains of aromatic residues, which is predicted to discriminate against the CoA thioesters. The PanK structure provides the framework for a more detailed understanding of the mechanism of catalysis and feedback regulation of PanK. Structural basis for the feedback regulation of Escherichia coli pantothenate kinase by coenzyme A.,Yun M, Park CG, Kim JY, Rock CO, Jackowski S, Park HW J Biol Chem. 2000 Sep 8;275(36):28093-9. PMID:10862768 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Pantothenate kinase 3D structures

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