title: Membrane topology of the STT3 subunit of the oligosaccharyl transferase complex.
abstract: The highly conserved membrane protein STT3 is part of the oligosaccharyl transferase complex in the endoplasmic reticulum of eukaryotic cells. Various experimental observations strongly suggest that STT3 contains the active site of the complex. Here, we report a detailed topology study of STT3 from two different organisms, Saccharomyces cerevisiae and mouse, using in vivo and in vitro topology mapping assays. Our results suggest that STT3 has 11 transmembrane helices and an overall N(cyt)-C(lum) orientation.
authors.affiliation: Department of Biochemistry and Biophysics, Stockholm University, SE-10691 Stockholm, Sweden.
authors.forename: Hyun
authors.initials: H
authors.lastname: Kim
authors.forename: Gunnar
authors.initials: G
authors.lastname: von Heijne
authors.forename: IngMarie
authors.initials: I
authors.lastname: Nilsson
mesh_terms: D000818:Animals; D001665:Binding Sites; D015153:Blotting, Western; D002462:Cell Membrane / Q000201:enzymology*; D003001:Cloning, Molecular; D004591:Electrophoresis, Polyacrylamide Gel; D006031:Glycosylation; D006602:Hexosyltransferases / Q000737:chemistry / Q000235:genetics; D017038:Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase / Q000378:metabolism; D008565:Membrane Proteins / Q000737:chemistry* / Q000235:genetics; D051379:Mice; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism; D017433:Protein Structure, Secondary; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; D012441:Saccharomyces cerevisiae / Q000201:enzymology; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000235:genetics; D043324:beta-Fructofuranosidase / Q000737:chemistry / Q000235:genetics
chemical_list: D008565:Membrane Proteins; D010446:Peptide Fragments; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; C502741:STT3-A protein, mouse; D029701:Saccharomyces cerevisiae Proteins; D006602:Hexosyltransferases; C096554:STT3 protein, S cerevisiae; C025620:dolichyl-diphosphooligosaccharide - protein glycotransferase; D043324:beta-Fructofuranosidase; D017038:Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase