1uh3

Thermoactinomyces vulgaris R-47 alpha-amylase/acarbose complex

spinqualitylabelsall models 1uh3, resolution 2.60Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1uh3 is a 1 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 2.6Å Ligands: ACI, BGC, CA, GLC, GLD, HSD, PRD_900001, PRD_900010, PRD_900023 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function NEPU1_THEVU Endohydrolysis of 1,4-alpha-glucosidic linkages in pullulan to form panose. Also hydrolyzes cyclodextrins. 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 X-ray structures of complexes of Thermoactinomyces vulgaris R-47 alpha-amylase 1 (TVAI) with an inhibitor acarbose and an inactive mutant TVAI with malto-hexaose and malto-tridecaose have been determined at 2.6, 2.0 and 1.8A resolution, and the structures have been refined to R-factors of 0.185 (R(free)=0.225), 0.184 (0.217) and 0.164 (0.200), respectively, with good chemical geometries. Acarbose binds to the catalytic site of TVAI, and interactions between acarbose and the enzyme are very similar to those found in other structure-solved alpha-amylase/acarbose complexes, supporting the proposed catalytic mechanism. Based on the structure of the TVAI/acarbose complex, the binding mode of pullulan containing alpha-(1,6) glucoside linkages could be deduced. Due to the structural difference caused by the replaced amino acid residue (Gln396 for Glu) in the catalytic site, malto-hexaose and malto-tridecaose partially bind to the catalytic site, giving a mimic of the enzyme/product complex. Besides the catalytic site, four sugar-binding sites on the molecular surface are found in these X-ray structures. Two sugar-binding sites in domain N hold the oligosaccharides with a regular helical structure of amylose, which suggests that the domain N is a starch-binding domain acting as an anchor to starch in the catalytic reaction of the enzyme. An assay of hydrolyzing activity for the raw starches confirmed that TVAI can efficiently hydrolyze raw starch. Complex structures of Thermoactinomyces vulgaris R-47 alpha-amylase 1 with malto-oligosaccharides demonstrate the role of domain N acting as a starch-binding domain.,Abe A, Tonozuka T, Sakano Y, Kamitori S J Mol Biol. 2004 Jan 16;335(3):811-22. PMID:14687576 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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