1o7q
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ROLES OF INDIVIDUAL RESIDUES OF ALPHA-1,3 GALACTOSYLTRANSFERASES IN SUBSTRATE BINDING AND CATALYSIS
OverviewOverview
The retaining glycosyltransferase, alpha-1,3-galactosyltransferase, (alpha3GT), is mutationally inactivated in humans, leading to the presence, of circulating antibodies against its product, the alpha-Gal epitope., alpha3GT catalyzes galactose transfer from UDP-Gal to beta-linked, galactosides, such as lactose, and in the absence of an acceptor, substrate, to water at a lower rate. We have used site-directed, mutagenesis to investigate the roles in catalysis and specificity of, residues in alpha3GT that form H-bonds as well as other interactions with, substrates. Mutation of the conserved Glu(317) to Gln weakens lactose, binding and reduces the k(cat) for galactosyltransfer to lactose and water, by 2400 and 120, respectively. The structure is not perturbed by this, substitution, but the ... [(full description)]
About this StructureAbout this Structure
1O7Q 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].
ReferenceReference
Roles of individual enzyme-substrate interactions by alpha-1,3-galactosyltransferase in catalysis and specificity., Zhang Y, Swaminathan GJ, Deshpande A, Boix E, Natesh R, Xie Z, Acharya KR, Brew K, Biochemistry. 2003 Nov 25;42(46):13512-21. PMID:14621997
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