1v2g

The L109P mutant of E. coli Thioesterase I/Protease I/Lysophospholipase L1 (TAP) in complexed with octanoic acid

spinqualitylabelsall models 1v2g, resolution 2.00Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1v2g is a 1 chain structure with sequence from "bacillus_coli"_migula_1895 "bacillus coli" migula 1895. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: IMD, OCA, SO4 Related: 1ivn, 1j00, 1jrl, 1nyv Gene: tesA, apeA, pldC ("Bacillus coli" Migula 1895) Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum Function [TESA_ECOLI] Hydrolyzes only long chain acyl thioesters (C12-C18). Specificity similar to chymotrypsin. 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 Escherichia coli thioesterase I/protease I/lysophospholipase L(1) (TAP) is a multifunctional lysophospholipase and acyl-CoA thioesterase with a SGNH-hydrolase fold. The relationship between TAP's structure and its versatile substrate specificity, however, is unclear. Here, we present the crystal structure of TAP in complex with octanoic acid (TAP-OCA; OCA, a free fatty acid with eight carbon atoms, C(8)). A structural comparison of native TAP with TAP-OCA reveals a remarkable conformational change in loop(75)(-)(80), called "switch loop movement", upon OCA binding to the substrate-binding crevice of TAP. OCA binding to the substrate-binding crevice results in a continuous hydrophobic surface, which triggers switch loop movement. The switch loop movement is acyl chain length dependent, with an effect of stabilizing the Michaelis complex (MC) of TAP during catalysis, and is essential for TAP's substrate preference. The finding of a sulfate ion binding site in the TAP structures, together with previous enzyme kinetic analyses, leads us to postulate that a putative CoA binding site is essential for efficient catalysis of thioesters in TAP. We also present the crystal structure of L109P-OCA (TAP's L109P mutant in complex with OCA), in which Leu109 mutated to Pro109 abolishes switch loop movement. This result strengthens our hypothesis that the switch loop movement is induced by hydrophobic interactions. Substrate specificities of Escherichia coli thioesterase I/protease I/lysophospholipase L1 are governed by its switch loop movement.,Lo YC, Lin SC, Shaw JF, Liaw YC Biochemistry. 2005 Feb 15;44(6):1971-9. PMID:15697222 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Thioesterase

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