EMD-4317
Cryo-EM Structure of the Mammalian Oligosaccharyltransferase Bound to Sec61 and the Non-programmed 80S Ribosome
EMD-4317
Single-particle4.7 Å
Deposition: 22/02/2018
Map released: 21/03/2018
Last modified: 29/07/2020
Sample Organism:
Rabbit,
Dog
Sample: Mammalian Oligosaccharyltransferase in complex with Sec61 and the non-programmed 80S Ribosome
Fitted models: 6ftj (Avg. Q-score: 0.174)
Deposition Authors: Braunger K, Becker T, Beckmann R
Sample: Mammalian Oligosaccharyltransferase in complex with Sec61 and the non-programmed 80S Ribosome
Fitted models: 6ftj (Avg. Q-score: 0.174)
Deposition Authors: Braunger K, Becker T, Beckmann R
Structural basis for coupling protein transport and N-glycosylation at the mammalian endoplasmic reticulum.
Braunger K ,
Pfeffer S ,
Shrimal S ,
Gilmore R ,
Berninghausen O ,
Mandon EC ,
Becker T ,
Forster F ,
Beckmann R
(2018) Science , 360 , 215 - 219
(2018) Science , 360 , 215 - 219
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.
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.