1vzx

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Revision as of 19:40, 29 October 2007

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spinqualitylabelsall models 1vzx, resolution 1.97Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

ROLES OF ACTIVE SITE TRYPTOPHANS IN SUBSTRATE BINDING AND CATALYSIS BY ALPHA-1,3 GALACTOSYLTRANSFERASE

Overview

Aromatic amino acids are frequent components of the carbohydrate binding, sites of lectins and enzymes. Previous structural studies have shown that, in alpha-1,3 galactosyltransferase, the binding site for disaccharide, acceptor substrates is encircled by four tryptophans, residues 249, 250, 314, and 356. To investigate their roles in enzyme specificity and, catalysis, we expressed and characterized variants of the catalytic domain, of alpha-1,3 galactosyltransferase with substitutions for each tryptophan., Substitution of glycine for tryptophan 249, whose indole ring interacts, with the nonpolar B face of glucose or GlcNAc, greatly increases the K(m), for the acceptor substrate. In contrast, the substitution of tyrosine for, tryptophan 314, which interacts with the beta-galactosyl moiety ... [(full description)]

About this Structure

1VZX is a [Single protein] structure of sequence from [Bos taurus] with MN, UDP and GOL as [ligands]. Active as [[1]], with EC number [2.4.1.151]. Full crystallographic information is available from [OCA].

Reference

Roles of active site tryptophans in substrate binding and catalysis by alpha-1,3 galactosyltransferase., Zhang Y, Deshpande A, Xie Z, Natesh R, Acharya KR, Brew K, Glycobiology. 2004 Dec;14(12):1295-302. Epub 2004 Jun 30. PMID:15229192

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