InterPro domain: IPR005013

Members of this family are involved in asparagine-linked protein glycosylation. In particular, dolichyl-diphosphooligosaccharide-protein glycosyltransferase (DDOST), also known as oligosaccharyltransferase ( 2.4.1.119 ), transfers the high-mannose sugar GlcNAc(2)-Man(9)-Glc(3) from a dolichol-linked donor to an asparagine acceptor in a consensus Asn-X-Ser/Thr motif. In most eukaryotes, the DDOST complex is composed of three subunits, which in humans are described as a 48kDa subunit, ribophorin I, and ribophorin II [ 1 ]. However, the yeast DDOST appears to consist of six subunits (alpha, beta, gamma, delta, epsilon, zeta). The yeast beta subunit is a 45kDa polypeptide, previously discovered as the Wbp1 protein, with known sequence similarity to the human 48kDa subunit and the other orthologues. This family includes the 48kDa-like subunits from several eukaryotes; it also includes the yeast DDOST beta subunit Wbp1.

Dolichyl-diphosphooligosaccharide--protein glycosyltransferase subunit Wbp1 is the beta subunit of the OST complex, one of the original six subunits purified [ 2 ]. Wbp1 is essential [ 3 , 4 ], but conditional mutants have decreased transferase activity [ 5 , 5 ].

1. [Side effects and complications in the external use of corticosteroids in dermatologic practice] Vestn Dermatol Venerol , 13-7
2. The Saccharomyces cerevisiae oligosaccharyltransferase is a protein complex composed of Wbp1p, Swp1p, and four additional polypeptides. J. Biol. Chem. 269, 12908-17
3. An essential 45 kDa yeast transmembrane protein reacts with anti-nuclear pore antibodies: purification of the protein, immunolocalization and cloning of the gene. Eur. J. Cell Biol. 56, 8-18
4. The yeast WBP1 is essential for oligosaccharyl transferase activity in vivo and in vitro. EMBO J. 11, 2071-5
5. Yeast Wbp1p and Swp1p form a protein complex essential for oligosaccharyl transferase activity. EMBO J. 12, 279-84