6W6L

Cryo-EM structure of the human ribosome-TMCO1 translocon

This is a non-PDB format compatible entry.

Summary for 6W6L

• Entry DOI: 10.2210/pdb6w6l/pdb
• EMDB information: 21426 21427 21435
• Descriptor: 60S ribosomal protein L8, 60S ribosomal protein L9, 60S ribosomal protein L10, ... (57 entities in total)
• Functional Keywords: ribosome-protein transport complex, ribosome/protein transport
• Biological source: Homo sapiens (Human); More
• Total number of polymer chains: 54
• Total formula weight: 2349794.40

Authors

Keenan, R.J.,McGilvray, P.T. (deposition date: 2020-03-17, release date: 2020-09-02, Last modification date: 2024-11-13)

Primary citation

McGilvray, P.T.,Anghel, S.A.,Sundaram, A.,Zhong, F.,Trnka, M.J.,Fuller, J.R.,Hu, H.,Burlingame, A.L.,Keenan, R.J.
An ER translocon for multi-pass membrane protein biogenesis.
Elife, 9:-, 2020

PubMed Abstract: Membrane proteins with multiple transmembrane domains play critical roles in cell physiology, but little is known about the machinery coordinating their biogenesis at the endoplasmic reticulum. Here we describe a ~ 360 kDa ribosome-associated complex comprising the core Sec61 channel and five accessory factors: TMCO1, CCDC47 and the Nicalin-TMEM147-NOMO complex. Cryo-electron microscopy reveals a large assembly at the ribosome exit tunnel organized around a central membrane cavity. Similar to protein-conducting channels that facilitate movement of transmembrane segments, cytosolic and luminal funnels in TMCO1 and TMEM147, respectively, suggest routes into the central membrane cavity. High-throughput mRNA sequencing shows selective translocon engagement with hundreds of different multi-pass membrane proteins. Consistent with a role in multi-pass membrane protein biogenesis, cells lacking different accessory components show reduced levels of one such client, the glutamate transporter EAAT1. These results identify a new human translocon and provide a molecular framework for understanding its role in multi-pass membrane protein biogenesis.

PubMed: 32820719
DOI: 10.7554/eLife.56889

Experimental method

ELECTRON MICROSCOPY (3.84 Å)