The BioGRID | PUBLICATION VIEW

	Glycobiology Dec (2005); 15(12):1396-406
The 3-4-kDa Ost4 protein is required for the assembly of two distinct oligosaccharyltransferase complexes in yeast-
Spirig U, Bodmer D, Wacker M, Burda P, Aebi M
Institute of Microbiology, ETH Zurich, CH-8093 Zurich, Switzerland-
Abstract: In the central reaction of N-linked glycosylation, the oligosaccharyltransferase -OTase- complex catalyzes the transfer of a lipid-linked core oligosaccharide onto asparagine residues of nascent polypeptide chains in the lumen of the endoplasmic reticulum -ER-- The Saccharomyces cerevisiae OTase has been shown to consist of at least eight subunits- We analyzed this enzyme complex, applying the technique of blue native gel electrophoresis- Using available antibodies, six different subunits were detected in the wild-type -wt- complex, including Stt3p, Ost1p, Wbp1p, Swp1p, Ost3p, and Ost6p- We demonstrate that the small 3-4-kDa subunit Ost4p is required for the incorporation of either Ost3p or Ost6p into the complex, resulting in two, functionally distinct OTase complexes in vivo- Ost3p and Ost6p are not absolutely required for OTase activity, but modulate the affinity of the enzyme toward different protein substrates-
[PUBMED: 16096346]