1y9m

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Revision as of 01:39, 25 November 2007

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spinqualitylabelsall models 1y9m, resolution 1.89Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

Crystal structure of exo-inulinase from Aspergillus awamori in spacegroup P212121

Overview

Exo-inulinases hydrolyze terminal, non-reducing 2,1-linked and 2,6-linked, beta-d-fructofuranose residues in inulin, levan and sucrose releasing, beta-d-fructose. We present the X-ray structure at 1.55A resolution of, exo-inulinase from Aspergillus awamori, a member of glycoside hydrolase, family 32, solved by single isomorphous replacement with the anomalous, scattering method using the heavy-atom sites derived from a quick, cryo-soaking technique. The tertiary structure of this enzyme folds into, two domains: the N-terminal catalytic domain of an unusual five-bladed, beta-propeller fold and the C-terminal domain folded into a, beta-sandwich-like structure. Its structural architecture is very similar, to that of another member of glycoside hydrolase family 32, invertase, (beta-fructosidase) from Thermotoga maritima, determined recently by X-ray, crystallography The exo-inulinase is a glycoprotein containing five, N-linked oligosaccharides. Two crystal forms obtained under similar, crystallization conditions differ by the degree of protein glycosylation., The X-ray structure of the enzyme:fructose complex, at a resolution of, 1.87A, reveals two catalytically important residues: Asp41 and Glu241, a, nucleophile and a catalytic acid/base, respectively. The distance between, the side-chains of these residues is consistent with a double displacement, mechanism of reaction. Asp189, which is part of the Arg-Asp-Pro motif, provides hydrogen bonds important for substrate recognition.

About this Structure

1Y9M is a Single protein structure of sequence from Aspergillus awamori with MAN, NAG and GOL as ligands. Active as Fructan beta-fructosidase, with EC number 3.2.1.80 Full crystallographic information is available from OCA.

Reference

Crystal structure of exo-inulinase from Aspergillus awamori: the enzyme fold and structural determinants of substrate recognition., Nagem RA, Rojas AL, Golubev AM, Korneeva OS, Eneyskaya EV, Kulminskaya AA, Neustroev KN, Polikarpov I, J Mol Biol. 2004 Nov 19;344(2):471-80. PMID:15522299

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