Reaction: UDP-N-acetyl-α-D-glucosamine + β-D-GlcNAc-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→6)]-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-β-D-GlcNAc-N-Asn-[protein] = UDP + β-D-GlcNAc-(1→2)-α-D-Man-(1→3)-[β-D-GlcNAc-(1→2)-α-D-Man-(1→6)]-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-β-D-GlcNAc-N-Asn-[protein]
For diagram of reaction click here.
Other name(s): MGAT2 (gene name); N-acetylglucosaminyltransferase II; N-glycosyl-oligosaccharide-glycoprotein N-acetylglucosaminyltransferase II; acetylglucosaminyltransferase II; uridine diphosphoacetylglucosamine-mannoside α1→6-acetylglucosaminyltransferase; uridine diphosphoacetylglucosamine-α-1,6-mannosylglycoprotein β-1-2-N-acetylglucosaminyltransferase; uridine diphosphoacetylglucosamine-α-D-mannoside β1-2-acetylglucosaminyltransferase; UDP-GlcNAc:mannoside α1-6 acetylglucosaminyltransferase; α-1,6-mannosyl-glycoprotein β-1,2-N-acetylglucosaminyltransferase; GnTII; GlcNAc-T II; UDP-N-acetyl-D-glucosamine:6-(α-D-mannosyl)-β-D-mannosyl-glycoprotein 2-β-N-acetyl-D-glucosaminyltransferase
Systematic name: UDP-N-acetyl-α-D-glucosamine:α-D-mannosyl-(1→6)-β-D-mannosyl-glycoprotein 2-β-N-acetyl-D-glucosaminyltransferase (configuration-inverting)
Comments: The enzyme, found in plants and animals, participates in the processing of N-glycans in the Golgi apparatus. Its activity initiates the synthesis of the second antenna of di-antennary complex N-glycans. While the natural substrate (produced by EC 3.2.1.114, mannosyl-oligosaccharide 1,3-1,6-α-mannosidase) is described here, the minimal substrate recognized by the enzyme is α-D-Man-(1→6)-[β-D-GlcNAc-(1→2)-α-D-Man-(1→3)]-β-D-Man-R.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 105913-04-0
References:
1. Harpaz, N. and Schachter, H. Control of glycoprotein synthesis. Bovine colostrum UDP-N-acetylglucosamine:α-D-mannoside β2-N-acetylglucosaminyltransferase I. Separation from UDP-N-acetylglucosamine:α-D-mannoside β2-N-acetylglucosaminyltransferase II, partial purification, and substrate specificity. J. Biol. Chem. 255 (1980) 4885-4893. [PMID: 6445358]
2. Mendicino, J., Chandrasekaran, E.V., Anumula, K.R. and Davila, M. Isolation and properties of α-D-mannose:β-1,2-N-acetylglucosaminyltransferase from trachea mucosa. Biochemistry 20 (1981) 967-976. [PMID: 6452163]
3. Oppenheimer, C.L., Eckhardt, A.E. and Hill, R.L. The nonidentity of porcine N-acetylglucosaminyltransferases I and II. J. Biol. Chem. 256 (1981) 11477-11482. [PMID: 6457827]
4. Schachter, H., Narasimhan, S., Gleeson, P. and Vella, G. Glycosyltransferases involved in elongation of N-glycosidically linked oligosaccharides of the complex or N-acetyllactosamine type. Methods Enzymol. 98 (1983) 98-134. [PMID: 6366476]
5. Bendiak, B. and Schachter, H. Control of glycoprotein synthesis. Kinetic mechanism, substrate specificity, and inhibition characteristics of UDP-N-acetylglucosamine:α-D-mannoside β-1-2 N-acetylglucosaminyltransferase II from rat liver. J. Biol. Chem. 262 (1987) 5784-5790. [PMID: 2952645]
6. Bendiak, B. and Schacter, H. Control of glycoprotein synthesis. Purification of UDP-N-acetylglucosamine:α-D-mannoside β1-2 N-acetylglucosaminyltransferase II from rat liver. J. Biol. Chem. 262 (1987) 5775-5783. [PMID: 2952644]
7. Tan, J., D'Agostaro, A.F., Bendiak, B., Reck, F., Sarkar, M., Squire, J.A., Leong, P. and Schachter, H. The human UDP-N-acetylglucosamine: α-6-D-mannoside-β-1,2- N-acetylglucosaminyltransferase II gene (MGAT2). Cloning of genomic DNA, localization to chromosome 14q21, expression in insect cells and purification of the recombinant protein. Eur. J. Biochem. 231 (1995) 317-328. [PMID: 7635144]