2vxn

E65Q-TIM complexed with phosphoglycolohydroxamate at 0.82 A resolution

spinqualitylabelsall models 2vxn, resolution 0.82Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2vxn is a 1 chain structure with sequence from Leime. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: ACT, GOL, PGA, PGH Related: 1n55, 1qds, 1amk, 1if2 Activity: Triose-phosphate isomerase, with EC number 5.3.1.1 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT 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 Enzymes achieve their catalytic proficiency by precisely positioning the substrate and catalytic residues with respect to each other. Atomic resolution crystallography is an excellent tool to study the important details of these geometric active-site features. Here, we have investigated the reaction mechanism of triosephosphate isomerase (TIM) using atomic resolution crystallographic studies at 0.82-A resolution of leishmanial TIM complexed with the well-studied reaction-intermediate analog phosphoglycolohydroxamate (PGH). Remaining unresolved aspects of the reaction mechanism of TIM such as the protonation state of the first reaction intermediate and the properties of the hydrogen-bonding interactions in the active site are being addressed. The hydroxamate moiety of PGH interacts via unusually short hydrogen bonds of its N1--O1 moiety with the carboxylate group of the catalytic glutamate (Glu167), for example, the distance of N1(PGH)-OE2(Glu167) is 2.69 +/- 0.01 A and the distance of O1(PGH)-OE1(Glu167) is 2.60 +/- 0.01 A. Structural comparisons show that the side chain of the catalytic base (Glu167) can move during the reaction cycle in a small cavity, located above the hydroxamate plane. The structure analysis suggests that the hydroxamate moiety of PGH is negatively charged. Therefore, the bound PGH mimics the negatively charged enediolate intermediate, which is formed immediately after the initial proton abstraction from DHAP by the catalytic glutamate. The new findings are discussed in the context of the current knowledge of the TIM reaction mechanism. Proteins 2010. (c) 2010 Wiley-Liss, Inc. Atomic resolution crystallography of a complex of triosephosphate isomerase with a reaction-intermediate analog: New insight in the proton transfer reaction mechanism.,Alahuhta M, Wierenga RK Proteins. 2010 Feb 16. PMID:20235230 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Triose Phosphate Isomerase

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