5A6U

Native mammalian ribosome-bound Sec61 protein-conducting channel in the 'non-inserting' state


Experimental Data Snapshot

  • Method: ELECTRON MICROSCOPY
  • Resolution: 9.00 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: TOMOGRAPHY 

wwPDB Validation   3D Report Full Report


This is version 2.1 of the entry. See complete history


Literature

Structure of the Native Sec61 Protein-Conducting Channel.

Pfeffer, S.Burbaum, L.Unverdorben, P.Pech, M.Chen, Y.Zimmermann, R.Beckmann, R.Forster, F.

(2015) Nat Commun 6: 8403

  • DOI: https://doi.org/10.1038/ncomms9403
  • Primary Citation of Related Structures:  
    5A6U

  • PubMed Abstract: 

    In mammalian cells, secretory and membrane proteins are translocated across or inserted into the endoplasmic reticulum (ER) membrane by the universally conserved protein-conducting channel Sec61, which has been structurally studied in isolated, detergent-solubilized states. Here we structurally and functionally characterize native, non-solubilized ribosome-Sec61 complexes on rough ER vesicles using cryo-electron tomography and ribosome profiling. Surprisingly, the 9-Å resolution subtomogram average reveals Sec61 in a laterally open conformation, even though the channel is not in the process of inserting membrane proteins into the lipid bilayer. In contrast to recent mechanistic models for polypeptide translocation and insertion, our results indicate that the laterally open conformation of Sec61 is the only conformation present in the ribosome-bound translocon complex, independent of its functional state. Consistent with earlier functional studies, our structure suggests that the ribosome alone, even without a nascent chain, is sufficient for lateral opening of Sec61 in a lipid environment.


  • Organizational Affiliation

    Department of Molecular Structural Biology, Max-Planck Institute of Biochemistry, Am Klopferspitz 18, D-82152 Martinsried, Germany.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
SEC61A451Canis lupus familiarisMutation(s): 0 
Membrane Entity: Yes 
UniProt
Find proteins for P38377 (Canis lupus familiaris)
Explore P38377 
Go to UniProtKB:  P38377
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP38377
Sequence Annotations
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  • Reference Sequence
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Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
SEC61B36Canis lupus familiarisMutation(s): 0 
Membrane Entity: Yes 
UniProt
Find proteins for P60467 (Canis lupus familiaris)
Explore P60467 
Go to UniProtKB:  P60467
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP60467
Sequence Annotations
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 3
MoleculeChains Sequence LengthOrganismDetailsImage
SEC61GC [auth G]62Canis lupus familiarisMutation(s): 0 
Membrane Entity: Yes 
UniProt
Find proteins for P60058 (Canis lupus familiaris)
Explore P60058 
Go to UniProtKB:  P60058
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP60058
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: ELECTRON MICROSCOPY
  • Resolution: 9.00 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: TOMOGRAPHY 
EM Software:
TaskSoftware PackageVersion
RECONSTRUCTIONAV3
RECONSTRUCTIONPyTom
RECONSTRUCTIONTOM Toolbox

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2015-10-07
    Type: Initial release
  • Version 1.1: 2015-10-28
    Changes: Database references
  • Version 2.0: 2017-08-23
    Changes: Advisory, Atomic model, Data collection, Derived calculations
  • Version 2.1: 2019-08-21
    Changes: Data collection