1vzx
From Proteopedia
|
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 [Transferred entry: 2.4.1.87], with EC number [2.4.1.151]. Structure known Active Site: AC1. 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
Page seeded by OCA on Tue Oct 30 16:20:32 2007
