Biological Assembly 1  

 3D View: Structure

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Hetero 3-mer - A1B1C1 

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 64.09 kDa 
• Atom Count: 3911 
• Residue Count: 514 
• Unique protein chains: 4

3JC2

The structure of the mammalian Sec61 channel opened by a signal sequence

• DOI: 10.2210/pdb3JC2/pdb
• EMDataResource: EMD-3245

• Classification: TRANSPORT PROTEIN
• Organism(s): Canis lupus familiaris, Bos taurus
• Expression System: Oryctolagus cuniculus
• Mutation(s): No 


• Deposited: 2015-11-15 Released: 2016-01-13 
• Deposition Author(s): Voorhees, R.M., Hegde, R.S.

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Experimental Data Snapshot

• Method: ELECTRON MICROSCOPY
• Resolution: 3.60 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SINGLE PARTICLE 

Literature

Structure of the Sec61 channel opened by a signal sequence.

Voorhees, R.M., Hegde, R.S.

(2016) Science 351: 88-91

• PubMed: 26721998 
• DOI: 10.1126/science.aad4992
• Primary Citation of Related Structures:  
  3JC2


• PubMed Abstract: 
  

Secreted and integral membrane proteins compose up to one-third of the biological proteome. These proteins contain hydrophobic signals that direct their translocation across or insertion into the lipid bilayer by the Sec61 protein-conducting channel. The molecular basis of how hydrophobic signals within a nascent polypeptide trigger channel opening is not understood. Here, we used cryo-electron microscopy to determine the structure of an active Sec61 channel that has been opened by a signal sequence. The signal supplants helix 2 of Sec61α, which triggers a rotation that opens the central pore both axially across the membrane and laterally toward the lipid bilayer. Comparisons with structures of Sec61 in other states suggest a pathway for how hydrophobic signals engage the channel to gain access to the lipid bilayer.

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Organizational Affiliation: 

MRC Laboratory of Molecular Biology, Medical Research Council, Francis Crick Avenue, Cambridge CB2 0QH, UK. [e-mail].

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Protein transport protein Sec61 subunit alpha isoform 1	1	476	Canis lupus familiaris	Mutation(s): 0  Gene Names: SEC61A1
Membrane protein Mpstruc	Group:  TRANSMEMBRANE PROTEINS: ALPHA-HELICAL		Sub Group:  Sec, Translocase, and Insertase Proteins	Protein:  Sec61 translocase opened by a signal sequence
Find proteins for P38377 (Canis lupus familiaris) Explore P38377  Go to UniProtKB:  P38377

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
Protein transport protein Sec61 subunit gamma	2	62	Canis lupus familiaris	Mutation(s): 0  Gene Names: SEC61G
Membrane protein Mpstruc	Group:  TRANSMEMBRANE PROTEINS: ALPHA-HELICAL		Sub Group:  Sec, Translocase, and Insertase Proteins	Protein:  Sec61 translocase opened by a signal sequence
Find proteins for P60058 (Canis lupus familiaris) Explore P60058  Go to UniProtKB:  P60058

Entity ID: 3
Molecule	Chains	Sequence Length	Organism	Details	Image
Prolactin	w	19	Bos taurus	Mutation(s): 0  Gene Names: prolactin, PRL
Membrane protein Mpstruc	Group:  TRANSMEMBRANE PROTEINS: ALPHA-HELICAL		Sub Group:  Sec, Translocase, and Insertase Proteins	Protein:  Sec61 translocase opened by a signal sequence
Find proteins for P01239 (Bos taurus) Explore P01239  Go to UniProtKB:  P01239

Entity ID: 4
Molecule	Chains	Sequence Length	Organism	Details	Image
Protein transport protein Sec61 subunit beta	3	32	Canis lupus familiaris	Mutation(s): 0

Experimental Data & Validation

Experimental Data

• Method: ELECTRON MICROSCOPY
• Resolution: 3.60 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SINGLE PARTICLE 

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2015-11-15 
• Released Date: 2016-01-13 
Deposition Author(s): Voorhees, R.M., Hegde, R.S.

Revision History 

• Version 1.0: 2016-01-13
  Type: Initial release
  
• Version 1.1: 2018-07-18
  Changes: Data collection