3kvi

Structural basis of the activity and substrate specificity of the fluoroacetyl-CoA thioesterase FlK - T42A mutant in complex with fluoro-acetate

spinqualitylabelsall models 3kvi, resolution 1.76Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3kvi is a 2 chain structure with sequence from Streptomyces cattleya. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.76Å Ligands: FAH Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function FLK_STRCT Hydrolyzes fluoroacetyl-CoA before it can react with citrate synthase, and thus confers fluoroacetate resistance. Can not use acetyl-CoA as substrate. 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 The thioesterase FlK from the fluoroacetate-producing Streptomyces cattleya catalyzes the hydrolysis of fluoroacetyl-coenzyme A. This provides an effective self-defense mechanism, preventing any fluoroacetyl-coenzyme A formed from being further metabolized to 4-hydroxy-trans-aconitate, a lethal inhibitor of the tricarboxylic acid cycle. Remarkably, FlK does not accept acetyl-coenzyme A as a substrate. Crystal structure analysis shows that FlK forms a dimer, in which each subunit adopts a hot dog fold as observed for type II thioesterases. Unlike other type II thioesterases, which invariably utilize either an aspartate or a glutamate as catalytic base, we show by site-directed mutagenesis and crystallography that FlK employs a catalytic triad composed of Thr(42), His(76), and a water molecule, analogous to the Ser/Cys-His-acid triad of type I thioesterases. Structural comparison of FlK complexed with various substrate analogues suggests that the interaction between the fluorine of the substrate and the side chain of Arg(120) located opposite to the catalytic triad is essential for correct coordination of the substrate at the active site and therefore accounts for the substrate specificity. Structural basis for the activity and substrate specificity of fluoroacetyl-CoA thioesterase FlK.,Dias MV, Huang F, Chirgadze DY, Tosin M, Spiteller D, Dry EF, Leadlay PF, Spencer JB, Blundell TL J Biol Chem. 2010 Jul 16;285(29):22495-504. Epub 2010 Apr 29. PMID:20430898 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Thioesterase 3D structures

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