Oligosaccharyltransferase
| STT3 | |||||||||
|---|---|---|---|---|---|---|---|---|---|
Structure of yeast OST | |||||||||
| Identifiers | |||||||||
| Symbol | STT3 | ||||||||
| Pfam | PF02516 | ||||||||
| Pfam clan | CL0111 | ||||||||
| InterPro | IPR003674 | ||||||||
| OPM superfamily | 242 | ||||||||
| OPM protein | 3rce | ||||||||
| CAZy | GT66 | ||||||||
| Membranome | 275 | ||||||||
| |||||||||
Oligosaccharyltransferase or OST (EC 2.4.1.119) is a membrane protein complex that transfers a 14-sugar oligosaccharide from dolichol to nascent protein. It is a type of glycosyltransferase. The sugar Glc3Man9GlcNAc2 (where Glc=Glucose, Man=Mannose, and GlcNAc=N-acetylglucosamine) is attached to an asparagine (Asn) residue in the sequence Asn-X-Ser or Asn-X-Thr where X is any amino acid except proline. This sequence is called a glycosylation sequon. The reaction catalyzed by OST is the central step in the N-linked glycosylation pathway.