2d0h

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spinqualitylabelsall models 2d0h, resolution 2.1Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

Crystal Structure of Thermoactinomyces vulgaris R-47 Alpha-Amylase 1 (TVAI) Mutant D356N/E396Q complexed with P2, a pullulan model oligosaccharide

Overview

Thermoactinomyces vulgaris R-47 alpha-amylase 1 (TVAI) has unique, hydrolyzing activities for pullulan with sequence repeats of alpha-(1,4), alpha-(1,4), and alpha-(1,6) glycosidic linkages, as well as for starch., TVAI mainly hydrolyzes alpha-(1,4) glycosidic linkages to produce a, panose, but it also hydrolyzes alpha-(1,6) glycosidic linkages with a, lesser efficiency. X-ray structures of three complexes comprising an, inactive mutant TVAI (D356N or D356N/E396Q) and a pullulan model, oligosaccharide (P2; [Glc-alpha-(1,6)-Glc-alpha-(1,4)-Glc-alpha-(1,4)]2 or, P5; [Glc-alpha-(1,6)-Glc-alpha-(1,4)-Glc-alpha-(1,4)]5) were determined., The complex D356N/P2 is a mimic of the enzyme/product complex in the main, catalytic reaction of TVAI, and a structural comparison with Aspergillus, oryzaealpha-amylase showed that the (-) subsites of TVAI are responsible, for recognizing both starch and pullulan. D356N/E396Q/P2 and, D356N/E396Q/P5 provided models of the enzyme/substrate complex recognizing, the alpha-(1,6) glycosidic linkage at the hydrolyzing site. They showed, that only subsites -1 and -2 at the nonreducing end of TVAI are effective, in the hydrolysis of alpha-(1,6) glycosidic linkages, leading to weak, interactions between substrates and the enzyme. Domain N of TVAI is a, starch-binding domain acting as an anchor in the catalytic reaction of the, enzyme. In this study, additional substrates were also found to bind to, domain N, suggesting that domain N also functions as a pullulan-binding, domain.

About this Structure

2D0H is a Single protein structure of sequence from Thermoactinomyces vulgaris with CA and MPD as ligands. Active as Alpha-amylase, with EC number 3.2.1.1 Full crystallographic information is available from OCA.

Reference

Complexes of Thermoactinomyces vulgaris R-47 alpha-amylase 1 and pullulan model oligossacharides provide new insight into the mechanism for recognizing substrates with alpha-(1,6) glycosidic linkages., Abe A, Yoshida H, Tonozuka T, Sakano Y, Kamitori S, FEBS J. 2005 Dec;272(23):6145-53. PMID:16302977

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