2APC

Crystal Structure of N-Acetylglucosaminyltransferase I in Complex with UDP-GlcNAc phosphonate

Summary for 2APC

• Entry DOI: 10.2210/pdb2apc/pdb
• Related: 1FO8 1FO9 1FOA
• Descriptor: Alpha-1,3-mannosyl-glycoprotein 2-beta-N-acetylglucosaminyltransferase, MANGANESE (II) ION, URIDINE-DIPHOSPHATE-METHYLENE-N-ACETYL-GLUCOSAMINE, ... (5 entities in total)
• Functional Keywords: transferase, n-acetylglucosaminyltransferase, glycosyltransferase, udp-glcnac, udp-glcnac phosphonate
• Biological source: Oryctolagus cuniculus (rabbit)
• Cellular location: Golgi apparatus membrane; Single-pass type II membrane protein: P27115
• Total number of polymer chains: 1
• Total formula weight: 40938.06

Authors

Rini, J.M.,Gordon, R.D. (deposition date: 2005-08-16, release date: 2006-06-27, Last modification date: 2024-11-20)

Primary citation

Gordon, R.D.,Sivarajah, P.,Satkunarajah, M.,Ma, D.,Tarling, C.A.,Vizitiu, D.,Withers, S.G.,Rini, J.M.
X-ray Crystal Structures of Rabbit N-acetylglucosaminyltransferase I (GnT I) in Complex with Donor Substrate Analogues.
J.Mol.Biol., 360:67-79, 2006

PubMed Abstract: 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.

PubMed: 16769084
DOI: 10.1016/j.jmb.2006.04.058

Experimental method

X-RAY DIFFRACTION (1.5 Å)