2yh2

Pyrobaculum calidifontis esterase monoclinic form

spinqualitylabelsall models 2yh2, resolution 2.20Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2yh2 is a 4 chain structure with sequence from Dsm 21063. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: SO4 Related: 2wir Activity: Carboxylesterase, with EC number 3.1.1.1 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Publication Abstract from PubMed The highly thermostable esterase from the hyperthermophilic archaeon Pyrobaculum calidifontis VA1 (PestE) shows high enantioselectivity (E > 100) in the kinetic resolution of racemic chiral carboxylic acids, but little selectivity towards acetates of tertiary alcohols (E = 2-4). To explain these unique properties, its crystal structure has been determined at 2.0 A resolution. The enzyme is a member of the hormone-sensitive lipase group (group H) of the esterase/lipase superfamily on the basis of the amino acid sequence identity. The PestE structure shows a canonical alpha/beta-hydrolase fold as core domain with a cap structure at the C-terminal end of the beta-sheet. A tetramer in the crystal packing is formed of two dimers; the dimeric form is observed in solution. Conserved dimers and even tetramers are found in other group H proteins. The amino acid residues Ser157, His284, and Asp254 form the catalytic triad, which is typically found in alpha/beta-hydrolases. The oxyanion hole is composed of Gly85 and Gly86 within the conserved sequence motif HGGG(M,F,W) (amino acid residues 83-87) and Ala158. With the elucidated structure, experimental results about enantioselectivity towards the two model substrate classes (as exemplified for 3-phenylbutanoic acid ethyl ester and 1,1,1-trifluoro-2-phenylbut-3-yn-2-yl acetate) could be explained by molecular modeling. For both enantiomers of the tertiary alcohol, orientations in two binding pockets were obtained without significant energy differences corresponding to the observed low enantioselectivity due to missing steric repulsions. In contrast, for the carboxylic acid ester, two different orientations with significant energy differences for each enantiomer were found matching the high E values. The crystal structure of an esterase from the hyperthermophilic microorganism Pyrobaculum calidifontis VA1 explains its enantioselectivity.,Palm GJ, Fernandez-Alvaro E, Bogdanovic X, Bartsch S, Sczodrok J, Singh RK, Bottcher D, Atomi H, Bornscheuer UT, Hinrichs W Appl Microbiol Biotechnol. 2011 Aug;91(4):1061-72. Epub 2011 May 26. PMID:21614503 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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