Structural basis for coupling protein transport and N-glycosylation at the mammalian endoplasmic reticulum

Braunger, Katharina; Pfeffer, Stefan; Shrimal, Shiteshu; Gilmore, Reid; Berninghausen, Otto; Mandon, Elisabet C.; Becker, Thomas; Förster, Friedrich und Beckmann, Roland (2018): Structural basis for coupling protein transport and N-glycosylation at the mammalian endoplasmic reticulum. In: Science, Vol. 360, No. 6385: pp. 215-218

Abstract

Protein synthesis, transport, and N-glycosylation are coupled at the mammalian endoplasmic reticulum by complex formation of a ribosome, the Sec61 protein-conducting channel, and oligosaccharyltransferase (OST). Here we used different cryo-electron microscopy approaches to determine structures of native and solubilized ribosome-Sec61-OST complexes. A molecular model for the catalytic OST subunit STT3A (staurosporine and temperature sensitive 3A) revealed how it is integrated into the OST and how STT3-paralog specificity for translocon-associated OST is achieved. The OST subunit DC2 was placed at the interface between Sec61 and STT3A, where it acts as a versatile module for recruitment of STT3A-containing OST to the ribosome-Sec61 complex. This detailed structural view on the molecular architecture of the cotranslational machinery for N-glycosylation provides the basis for a mechanistic understanding of glycoprotein biogenesis at the endoplasmic reticulum.

• Item Type: Journal article
• Faculties: Chemistry and Pharmacy > Department of Biochemistry
• Subjects: 500 Science > 540 Chemistry
• ISSN: 0036-8075
• Language: English