Accepted name: dolichyl-phosphooligosaccharide-protein glycotransferase
Reaction: an archaeal dolichyl phosphooligosaccharide + [protein]-L-asparagine = an archaeal dolichyl phosphate + a glycoprotein with the oligosaccharide chain attached by N-β-D-glycosyl linkage to a protein L-asparagine
Other name(s): AglB; archaeal oligosaccharyl transferase; dolichyl-monophosphooligosaccharide-protein glycotransferase
Systematic name: dolichyl-phosphooligosaccharide:protein-L-asparagine N-β-D-oligosaccharidotransferase
Comments: The enzyme, characterized from the archaea Methanococcus voltae and Haloferax volcanii, transfers a glycan component from dolichyl phosphooligosaccharide to external proteins. It is different from EC, dolichyl-diphosphooligosaccharide-protein glycotransferase, which uses dolichyl diphosphate as carrier compound in bacteria and eukaryotes. The enzyme participates in the N-glycosylation of proteins in some archaea. It requires Mn2+. Dolichol used by archaea is different from that used by eukaryotes. It is much shorter (C55-C60), it is α,ω-saturated and it may have additional unsaturated positions in the chain.
1.  Chaban, B., Voisin, S., Kelly, J., Logan, S.M. and Jarrell, K.F. Identification of genes involved in the biosynthesis and attachment of Methanococcus voltae N-linked glycans: insight into N-linked glycosylation pathways in Archaea. Mol. Microbiol. 61 (2006) 259–268. [PMID: 16824110]
2.  Larkin, A., Chang, M.M., Whitworth, G.E. and Imperiali, B. Biochemical evidence for an alternate pathway in N-linked glycoprotein biosynthesis. Nat. Chem. Biol. 9 (2013) 367–373. [PMID: 23624439]
3.  Cohen-Rosenzweig, C., Guan, Z., Shaanan, B. and Eichler, J. Substrate promiscuity: AglB, the archaeal oligosaccharyltransferase, can process a variety of lipid-linked glycans. Appl. Environ. Microbiol. 80 (2014) 486–496. [PMID: 24212570]
[EC created 2015]