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Complex of alpha-amylase II (TVA II) from Thermoactinomyces vulgaris R-47 with beta-cyclodextrin based on a co-crystallization with methyl beta-cyclodextrinComplex of alpha-amylase II (TVA II) from Thermoactinomyces vulgaris R-47 with beta-cyclodextrin based on a co-crystallization with methyl beta-cyclodextrin
Structural highlights
FunctionNEPU2_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 ConservationCheck, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe structures of Thermoactinomyces vulgaris R-47 alpha-amylase II mutant (d325nTVA II) complexed with substrate analogues, methyl beta-cyclodextrin (m beta-CD) and maltohexaose (G6), were solved by X-ray diffraction at 3.2 A and 3.3 A resolution, respectively. In d325nTVA II-m beta-CD complex, the orientation and binding-position of beta-CD in TVA II were identical to those in cyclodextin glucanotransferase (CGTase). The active site residues were essentialy conserved, while there are no residues corresponding to Tyr89, Phe183, and His233 of CGTase in TVA II. In d325nTVA II-G6 complex, the electron density maps of two glucosyl units at the non-reducing end were disordered and invisible. The four glucosyl units of G6 were bound to TVA II as in CGTase, while the others were not stacked and were probably flexible. The residues of TVA II corresponding to Tyr89, Lys232, and His233 of CGTase were completely lacking. These results suggest that the lack of the residues related to alpha-glucan and CD-stacking causes the functional distinctions between CGTase and TVA II. Structures of Thermoactinomyces vulgaris R-47 alpha-amylase II complexed with substrate analogues.,Yokota T, Tonozuka T, Shimura Y, Ichikawa K, Kamitori S, Sakano Y Biosci Biotechnol Biochem. 2001 Mar;65(3):619-26. PMID:11330677[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences |
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