7KRA image
Entry Detail
PDB ID:
7KRA
EMDB ID:
Title:
Cryo-EM structure of Saccharomyces cerevisiae ER membrane protein complex bound to Fab-DH4 in lipid nanodiscs
Biological Source:
PDB Version:
Deposition Date:
2020-11-19
Release Date:
2020-12-02
Method Details:
Experimental Method:
Resolution:
3.20 Å
Aggregation State:
PARTICLE
Reconstruction Method:
SINGLE PARTICLE
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:ER membrane protein complex subunit 1
Chain IDs:A
Chain Length:760
Number of Molecules:1
Biological Source:Saccharomyces cerevisiae
Polymer Type:polypeptide(L)
Description:ER membrane protein complex subunit 2
Chain IDs:B
Chain Length:292
Number of Molecules:1
Biological Source:Saccharomyces cerevisiae
Polymer Type:polypeptide(L)
Description:ER membrane protein complex subunit 3
Chain IDs:C
Chain Length:253
Number of Molecules:1
Biological Source:Saccharomyces cerevisiae
Polymer Type:polypeptide(L)
Description:ER membrane protein complex subunit 4
Chain IDs:D
Chain Length:190
Number of Molecules:1
Biological Source:Saccharomyces cerevisiae
Polymer Type:polypeptide(L)
Description:ER membrane protein complex subunit 5
Chain IDs:E
Chain Length:182
Number of Molecules:1
Biological Source:Saccharomyces cerevisiae
Polymer Type:polypeptide(L)
Description:ER membrane protein complex subunit 6
Chain IDs:F
Chain Length:108
Number of Molecules:1
Biological Source:Saccharomyces cerevisiae
Polymer Type:polypeptide(L)
Description:Protein SOP4
Chain IDs:G
Chain Length:234
Number of Molecules:1
Biological Source:Saccharomyces cerevisiae
Polymer Type:polypeptide(L)
Description:Endoplasmic reticulum membrane protein complex subunit 10
Chain IDs:H
Chain Length:205
Number of Molecules:1
Biological Source:Saccharomyces cerevisiae
Polymer Type:polypeptide(L)
Description:Fab DH4 heavy chain
Chain IDs:I
Chain Length:254
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Description:Fab DH4 light chain
Chain IDs:J
Chain Length:234
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Description:Unassigned helix
Chain IDs:K (auth: M), L (auth: N)
Chain Length:24
Number of Molecules:2
Biological Source:Saccharomyces cerevisiae
Primary Citation
Structural and mechanistic basis of the EMC-dependent biogenesis of distinct transmembrane clients.
Elife 9 ? ? (2020)
PMID: 33236988 DOI: 10.7554/eLife.62611

Abstact

Membrane protein biogenesis in the endoplasmic reticulum (ER) is complex and failure-prone. The ER membrane protein complex (EMC), comprising eight conserved subunits, has emerged as a central player in this process. Yet, we have limited understanding of how EMC enables insertion and integrity of diverse clients, from tail-anchored to polytopic transmembrane proteins. Here, yeast and human EMC cryo-EM structures reveal conserved intricate assemblies and human-specific features associated with pathologies. Structure-based functional studies distinguish between two separable EMC activities, as an insertase regulating tail-anchored protein levels and a broader role in polytopic membrane protein biogenesis. These depend on mechanistically coupled yet spatially distinct regions including two lipid-accessible membrane cavities which confer client-specific regulation, and a non-insertase EMC function mediated by the EMC lumenal domain. Our studies illuminate the structural and mechanistic basis of EMC's multifunctionality and point to its role in differentially regulating the biogenesis of distinct client protein classes.

Legend

Protein

Chemical

Disease

Primary Citation of related structures