The oligosaccharyltransferase complexes (OST) are multi-span ER membrane protein complexes that catalyzes the addition of glycans to selected secretory and membrane protein polypeptides in the ER lumnen. They transfers the dolicholphosphate-linked core oligosaccharide to selected Asn residues within the motif Asn-X-Ser/Thr in a process termed N-glycosylation. The OSTB complex acts post-translationally and mediates the N-glycosylation of sites that are skipped by OSTA. (Adapted from
PMID:31810196.)
