Studies of yeast oligosaccharyl transferase subunits using the split-ubiquitin system: topological features and in vivo interactions.

ABSTRACT: Oligosaccharyl transferase (OT) catalyzes the cotranslational N-glycosylation of nascent polypeptides in the endoplasmic reticulum in all eukaryotic systems. Due to the inherent difficulty in characterizing this membrane protein complex, the mode of enzymatic action has not been resolved. Here, we used a membrane protein two-hybrid approach, the split-ubiquitin system, to address two aspects of the enzyme complex in yeast: the topological features, as well as the in vivo interactions of all of the components. We investigated the N- and C-terminal orientation of these proteins and the presence or the absence of a cleavable signal sequence at their N termini. We found that Ost2p and Stt3p have only their N terminus located in the cytosol, whereas Ost3p and Swp1p have only their C terminus or

SUBMITTER: Yan A 

PROVIDER: S-EPMC1129144 | biostudies-literature | 2005 May

REPOSITORIES: biostudies-literature