This family contains eukaryotic Ribophorin II (RPN2) proteins. The mammalian oligosaccharyltransferase (OST) is a protein complex that effects the cotranslational N-glycosylation of newly synthesised polypeptides, and is composed of the following proteins: ribophorins I and II (RI and RII), OST48, and Dadl, N33/IAP, OST4, STT3. The family also includes the SWP1 protein from yeast. In yeast the oligosaccharyltransferase complex is composed 7 or 8 subunits, SWP1, being one of them [2][3].

1: Localization of ribophorin II to the endoplasmic reticulum involves both its transmembrane and cytoplasmic domains. Fu J, Pirozzi G, Sanjay A, Levy R, Chen Y, De Lemos-Chiarandini C, Sabatini D, Kreibich G; Eur J Cell Biol 2000;79:219-228. PMID:10826490

2: The Saccharomyces cerevisiae oligosaccharyltransferase is a protein complex composed of Wbp1p, Swp1p, and four additional polypeptides. Kelleher DJ, Gilmore R; J Biol Chem. 1994;269:12908-12917. PMID:8175708

3: Studies of yeast oligosaccharyl transferase subunits using the split-ubiquitin system: topological features and in vivo interactions. Yan A, Wu E, Lennarz WJ; Proc Natl Acad Sci U S A. 2005;102:7121-7126. PMID:15886282