1foa
CRYSTAL STRUCTURE OF N-ACETYLGLUCOSAMINYLTRANSFERASE I
|
OverviewOverview
N:-acetylglucosaminyltransferase I (GnT I) serves as the gateway from, oligomannose to hybrid and complex N:-glycans and plays a critical role in, mammalian development and possibly all metazoans. We have determined the, X-ray crystal structure of the catalytic fragment of GnT I in the absence, and presence of bound UDP-GlcNAc/Mn(2+) at 1.5 and 1.8 A resolution, respectively. The structures identify residues critical for substrate, binding and catalysis and provide evidence for similarity, at the, mechanistic level, to the deglycosylation step of retaining, beta-glycosidases. The structuring of a 13 residue loop, resulting from, UDP-GlcNAc/Mn(2+) binding, provides an explanation for the ordered, sequential 'Bi Bi' kinetics shown by GnT I. Analysis reveals a domain, shared with Bacillus subtilis glycosyltransferase SpsA, bovine, beta-1,4-galactosyl transferase 1 and Escherichia coli, N:-acetylglucosamine-1-phosphate uridyltransferase. The low sequence, identity, conserved fold and related functional features shown by this, domain define a superfamily whose members probably share a common, ancestor. Sequence analysis and protein threading show that the domain is, represented in proteins from several glycosyltransferase families.
About this StructureAbout this Structure
1FOA is a Single protein structure of sequence from Oryctolagus cuniculus with MN, UD1 and GOL as ligands. Active as Alpha-1,3-mannosyl-glycoprotein 2-beta-N-acetylglucosaminyltransferase, with EC number 2.4.1.101 Full crystallographic information is available from OCA.
ReferenceReference
X-ray crystal structure of rabbit N-acetylglucosaminyltransferase I: catalytic mechanism and a new protein superfamily., Unligil UM, Zhou S, Yuwaraj S, Sarkar M, Schachter H, Rini JM, EMBO J. 2000 Oct 16;19(20):5269-80. PMID:11032794
Page seeded by OCA on Tue Nov 20 15:05:21 2007