2am5
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Crystal Structure of N-Acetylglucosaminyltransferase I in Complex with UDP
OverviewOverview
The Golgi-resident glycosyltransferase, UDP-N-acetyl-d-glucosamine:alpha-3-d-mannoside, beta-1,2-N-acetylglucosaminyltransferase I (GnT I), initiates the, conversion of high-mannose oligosaccharides to complex and hybrid, structures in the biosynthesis of N-linked glycans. Reported here are the, X-ray crystal structures of GnT I in complex with UDP-CH2-GlcNAc (a, non-hydrolyzable C-glycosidic phosphonate), UDP-2-deoxy-2-fluoro-glucose, UDP-glucose and UDP. Collectively, these structures provide evidence for, the importance of the GlcNAc moiety and its N-acetyl group in donor, substrate binding, as well as insight into the role played by the flexible, 318-330 loop in substrate binding and product release. In addition, the, UDP-CH2-GlcNAc complex reveals a well-defined glycerol molecule poised for, nucleophilic attack on the C1 atom of the donor substrate analogue. The, position and orientation of this glycerol molecule have allowed us to, model the binding of the Manalpha1,3Manbeta1 moiety of the acceptor, substrate and, based on the model, to suggest a rationalization for the, main determinants of GnT I acceptor specificity.
About this StructureAbout this Structure
2AM5 is a Single protein structure of sequence from Oryctolagus cuniculus with MN, UDP 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 structures of rabbit N-acetylglucosaminyltransferase I (GnT I) in complex with donor substrate analogues., Gordon RD, Sivarajah P, Satkunarajah M, Ma D, Tarling CA, Vizitiu D, Withers SG, Rini JM, J Mol Biol. 2006 Jun 30;360(1):67-79. Epub 2006 May 12. PMID:16769084
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