2d2o

Structure of a complex of Thermoactinomyces vulgaris R-47 alpha-amylase 2 with maltohexaose demonstrates the important role of aromatic residues at the reducing end of the substrate binding cleft

spinqualitylabelsall models 2d2o, resolution 2.10Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2d2o is a 2 chain structure with sequence from Thermoactinomyces vulgaris. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.1Å Ligands: CA, GLC, PRD_900035 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function NEPU2_THEVU Hydrolyzes pullulan efficiently but only a small amount of starch. Endohydrolysis of 1,4-alpha-glucosidic linkages in pullulan to form panose. Cleaves also (1-6)-alpha-glucosidic linkages to form maltotriose. 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 Thermoactinomyces vulgaris R-47 alpha-amylase 2 (TVAII) can efficiently hydrolyze both starch and cyclomaltooligosaccharides (cyclodextrins). The crystal structure of an inactive mutant TVAII in a complex with maltohexaose was determined at a resolution of 2.1A. TVAII adopts a dimeric structure to form two catalytic sites, where substrates are found to bind. At the catalytic site, there are many hydrogen bonds between the enzyme and substrate at the non-reducing end from the hydrolyzing site, but few hydrogen bonds at the reducing end, where two aromatic residues, Trp356 and Tyr45, make effective interactions with a substrate. Trp356 drastically changes its side-chain conformation to achieve a strong stacking interaction with the substrate, and Tyr45 from another molecule forms a water-mediated hydrogen bond with the substrate. Kinetic analysis of the wild-type and mutant enzymes in which Trp356 and/or Tyr45 were replaced with Ala suggested that Trp356 and Tyr45 are essential to the catalytic reaction of the enzyme, and that the formation of a dimeric structure is indispensable for TVAII to hydrolyze both starch and cyclodextrins. Structure of a complex of Thermoactinomyces vulgaris R-47 alpha-amylase 2 with maltohexaose demonstrates the important role of aromatic residues at the reducing end of the substrate binding cleft.,Ohtaki A, Mizuno M, Yoshida H, Tonozuka T, Sakano Y, Kamitori S Carbohydr Res. 2006 Jun 12;341(8):1041-6. Epub 2006 Mar 27. PMID:16564038 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Amylase 3D structures

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