This entry represents the C-terminal core domain found in the oligosaccharyl transferase STT3 subunit and related proteins, such as bacterial PglB and archaeal AlgB. STT3 is part of the oligosccharyl transferase (OTase) complex and required for its activity, which transfers a lipid-linked core-oligosaccharide to selected asparagine residues in the ER. In the archaea STT3 occurs alone, rather than in an OTase complex, and is required for N-glycosylation of asparagines [1-5]. This is a globular domain which adopts a mixed alpha/beta fold and contains the highly conserved WWDYG motif, in which the aspartate residue is thought to function as a catalytic residue [1-5].

1: Eukaryotic N-glycosylation occurs via the membrane-anchored C-terminal domain of the Stt3p subunit of oligosaccharyltransferase. Huang C, Bhaskaran R, Mohanty S; J Biol Chem. 2012;287:32450-32458. PMID:22865878

2: Structure-guided identification of a new catalytic motif of oligosaccharyltransferase. Igura M, Maita N, Kamishikiryo J, Yamada M, Obita T, Maenaka K, Kohda D; EMBO J. 2008;27:234-243. PMID:18046457

3: Comparative structural biology of eubacterial and archaeal oligosaccharyltransferases. Maita N, Nyirenda J, Igura M, Kamishikiryo J, Kohda D; J Biol Chem. 2010;285:4941-4950. PMID:20007322

4: X-ray structure of a bacterial oligosaccharyltransferase. Lizak C, Gerber S, Numao S, Aebi M, Locher KP; Nature. 2011;474:350-355. PMID:21677752

5: Crystallographic and NMR evidence for flexibility in oligosaccharyltransferases and its catalytic significance. Nyirenda J, Matsumoto S, Saitoh T, Maita N, Noda NN, Inagaki F, Kohda D; Structure. 2013;21:32-41. PMID:23177926