2gam

X-ray crystal structure of murine leukocyte-type Core 2 b1,6-N-acetylglucosaminyltransferase (C2GnT-L) in complex with Galb1,3GalNAc

spinqualitylabelsall models 2gam, resolution 2.70Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2gam is a 4 chain structure with sequence from Lk3 transgenic mice. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: GAL, NGA Related: 2gak Gene: Gcnt1 (LK3 transgenic mice) Activity: Beta-1,3-galactosyl-O-glycosyl-glycoprotein beta-1,6-N- acetylglucosaminyltransferase, with EC number 2.4.1.102 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum Function [GCNT1_MOUSE] Forms critical branches in O-glycans. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed Leukocyte type core 2 beta1,6-N-acetylglucosaminyltransferase (C2GnT-L) is a key enzyme in the biosynthesis of branched O-glycans. It is an inverting, metal ion-independent family 14 glycosyltransferase that catalyzes the formation of the core 2 O-glycan (Galbeta1-3[GlcNAcbeta1-6]GalNAc-O-Ser/Thr) from its donor and acceptor substrates, UDP-GlcNAc and the core 1 O-glycan (Galbeta1-3GalNAc-O-Ser/Thr), respectively. Reported here are the x-ray crystal structures of murine C2GnT-L in the absence and presence of the acceptor substrate Galbeta1-3GalNAc at 2.0 and 2.7A resolution, respectively. C2GnT-L was found to possess the GT-A fold; however, it lacks the characteristic metal ion binding DXD motif. The Galbeta1-3GalNAc complex defines the determinants of acceptor substrate binding and shows that Glu-320 corresponds to the structurally conserved catalytic base found in other inverting GT-A fold glycosyltransferases. Comparison of the C2GnT-L structure with that of other GT-A fold glycosyltransferases further suggests that Arg-378 and Lys-401 serve to electrostatically stabilize the nucleoside diphosphate leaving group, a role normally played by metal ion in GT-A structures. The use of basic amino acid side chains in this way is strikingly similar to that seen in a number of metal ion-independent GT-B fold glycosyltransferases and suggests a convergence of catalytic mechanism shared by both GT-A and GT-B fold glycosyltransferases. X-ray crystal structure of leukocyte type core 2 beta1,6-N-acetylglucosaminyltransferase. Evidence for a convergence of metal ion-independent glycosyltransferase mechanism.,Pak JE, Arnoux P, Zhou S, Sivarajah P, Satkunarajah M, Xing X, Rini JM J Biol Chem. 2006 Sep 8;281(36):26693-701. Epub 2006 Jul 7. PMID:16829524 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also O-GlcNAc transferase

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