1fg5
CRYSTAL STRUCTURE OF BOVINE ALPHA-1,3-GALACTOSYLTRANSFERASE CATALYTIC DOMAIN.
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OverviewOverview
alpha1,3-galactosyltransferase (alpha3GalT, EC 2.4.1.151) is a, Golgi-resident, type II transmembrane protein that transfers galactose, from UDP-alpha-galactose to the terminal N:-acetyllactosamine unit of, glycoconjugate glycans, producing the Galalpha1,3Galbeta1,4GlcNAc, oligosaccharide structure present in most mammalian glycoproteins. Unlike, most other mammals, humans and Old World primates do not possess, alpha3GalT activity, which is relevant for the hyperacute rejection, observed in pig-to-human xenotransplantation. The crystal structure of the, catalytic domain of substrate-free bovine alpha3GalT, solved and refined, to 2.3 A resolution, has a globular shape with an alpha/beta fold, containing a narrow cleft on one face, and shares a UDP-binding domain, (UBD) with the recently solved inverting glycosyltransferases. The, substrate-bound complex, solved and refined to 2.5 A, allows the, description of residues interacting directly with UDP-galactose. These, structural data suggest that the strictly conserved residue E317 is likely, to be the catalytic nucleophile involved in galactose transfer with, retention of anomeric configuration as accomplished by this enzyme., Moreover, the alpha3GalT structure helps to identify amino acid residues, that determine the specificities of the highly homologous ABO histo-blood, group and glycosphingolipid glycosyltransferases.
About this StructureAbout this Structure
1FG5 is a Single protein structure of sequence from Bos taurus. Active as N-acetyllactosaminide 3-alpha-galactosyltransferase, with EC number 2.4.1.87 Full crystallographic information is available from OCA.
ReferenceReference
Bovine alpha1,3-galactosyltransferase catalytic domain structure and its relationship with ABO histo-blood group and glycosphingolipid glycosyltransferases., Gastinel LN, Bignon C, Misra AK, Hindsgaul O, Shaper JH, Joziasse DH, EMBO J. 2001 Feb 15;20(4):638-49. PMID:11179209
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