This entry consists of the oligosaccharyl transferase STT3 subunit and related proteins. The STT3 subunit is part of the oligosaccharyl transferase (OTase) complex of proteins and is required for its activity [2]. In eukaryotes, OTase transfers a l ...
This entry consists of the oligosaccharyl transferase STT3 subunit and related proteins. The STT3 subunit is part of the oligosaccharyl transferase (OTase) complex of proteins and is required for its activity [2]. In eukaryotes, OTase transfers a lipid-linked core-oligosaccharide to selected asparagine residues in the ER [2]. In the archaea STT3 occurs alone, rather than in an OTase complex, and is required for N-glycosylation of asparagines [3-4]. This entry represents the N-terminal domain, consisting of transmembrane helices.
This entry represents the C-terminal core domain of archaeal oligosaccharyltransferase AglB that transfers oligosaccharide chain from a lipid-linked oligosaccharide (LLO) donor to the asparagine residues in the N-glycosylation sequon, Asn-X-Ser/Thr ( ...
This entry represents the C-terminal core domain of archaeal oligosaccharyltransferase AglB that transfers oligosaccharide chain from a lipid-linked oligosaccharide (LLO) donor to the asparagine residues in the N-glycosylation sequon, Asn-X-Ser/Thr (X=Pro) [1-5]. In the archaea AlgB, it occurs alone, rather than in complex as the eukaryotic homologue STT3. This domain adopts a mixed alpha/beta fold and contains a highly conserved WWDYG motif that may be of functional relevance.
Members of this entry are involved in asparagine-linked protein glycosylation. In particular, dolichyl-diphosphooligosaccharide-protein glycosyltransferase (DDOST), also known as oligosaccharyltransferase, transfers the high-mannose sugar GlcNAc(2)-M ...
Members of this entry are involved in asparagine-linked protein glycosylation. In particular, dolichyl-diphosphooligosaccharide-protein glycosyltransferase (DDOST), also known as oligosaccharyltransferase, 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 48kD subunit, ribophorin I, and ribophorin II. However, the yeast DDOST appears to consist of six subunits (alpha, beta, gamma, delta, epsilon, zeta). The yeast beta subunit is a 45kD polypeptide, previously discovered as the Wbp1 protein, with known sequence similarity to the human 48kD subunit and the other orthologues. This is the N-terminal domain of OST48 subunits from animals and plants and the orthologue from yeast Wbp1. This domain is distantly related to the IFT52 N-terminal domain (Pfam:PF23355).
The Sec61/SecY translocon mediates translocation of proteins across the membrane and integration of membrane proteins into the lipid bilayer. The structure of the translocon revealed a plug domain blocking the pore on the lumenal side.The plug is unl ...
The Sec61/SecY translocon mediates translocation of proteins across the membrane and integration of membrane proteins into the lipid bilayer. The structure of the translocon revealed a plug domain blocking the pore on the lumenal side.The plug is unlikely to be important for sealing the translocation pore in yeast but it plays a role in stabilising Sec61p during translocon formation. The domain runs from residues 52-74 [1].