Biological Assembly 1  

 3D View: Structure | 1D-3D View | Electron Density | Validation Report | Predict Membrane 

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Hetero 5-mer - A2B1C1D1 Pseudo Symmetry: Cyclic - C5  (3D View)
Pseudo Stoichiometry: Homo 5-mer - A5 

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 278.07 kDa 
• Atom Count: 14924 
• Modelled Residue Count: 1851 
• Deposited Residue Count: 2425 
• Unique protein chains: 4

4AQ5

Gating movement in acetylcholine receptor analysed by time-resolved electron cryo-microscopy (closed class)

• PDB DOI: 10.2210/pdb4AQ5/pdb
• EM Map EMD-2071: EMDB EMDataResource

• Classification: MEMBRANE PROTEIN
• Organism(s): Torpedo marmorata
• Mutation(s): No 
• Membrane Protein: Yes  PDBTMMemProtMDmpstruc


• Deposited: 2012-04-12 Released: 2012-08-01 
• Deposition Author(s): Unwin, N., Fujiyoshi, Y.

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Experimental Data Snapshot

• Method: ELECTRON MICROSCOPY
• Resolution: 6.20 Å
• Aggregation State: HELICAL ARRAY 
• Reconstruction Method: HELICAL 

Literature

Gating Movement of Acetylcholine Receptor Caught by Plunge-Freezing.

Unwin, N., Fujiyoshi, Y.

(2012) J Mol Biol 422: 617

• PubMed: 22841691 
• DOI: 10.1016/j.jmb.2012.07.010
• Primary Citation of Related Structures:  
  4AQ5, 4AQ9


• PubMed Abstract: 
  

The nicotinic acetylcholine (ACh) receptor converts transiently to an open-channel form when activated by ACh released into the synaptic cleft. We describe here the conformational change underlying this event, determined by electron microscopy of ACh-sprayed and freeze-trapped postsynaptic membranes. ACh binding to the α subunits triggers a concerted rearrangement in the ligand-binding domain, involving an ~1-Å outward displacement of the extracellular portion of the β subunit where it interacts with the juxtaposed ends of α-helices shaping the narrow membrane-spanning pore. The β-subunit helices tilt outward to accommodate this displacement, destabilising the arrangement of pore-lining helices, which in the closed channel bend inward symmetrically to form a central hydrophobic gate. Straightening and tangential motion of the pore-lining helices effect channel opening by widening the pore asymmetrically and increasing its polarity in the region of the gate. The pore-lining helices of the α(γ) and δ subunits, by flexing between alternative bent and straight conformations, undergo the greatest movements. This coupled allosteric transition shifts the structure from a tense (closed) state toward a more relaxed (open) state.

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Organizational Affiliation: 

Department of Biophysics, Faculty of Science, Kyoto University, Oiwake, Kitashirakawa, Sakyo-ku, Kyoto 606-8502, Japan.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
ACETYLCHOLINE RECEPTOR SUBUNIT ALPHA	A, D	461	Torpedo marmorata	Mutation(s): 0  Gene Names: CHRNA1 Membrane Entity: Yes
UniProt
Find proteins for P02711 (Torpedo marmorata) Explore P02711  Go to UniProtKB:  P02711

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
ACETYLCHOLINE RECEPTOR BETA SUBUNIT	B	493	Torpedo marmorata	Mutation(s): 0  Membrane Entity: Yes
UniProt
Find proteins for Q6S3I0 (Torpedo marmorata) Explore Q6S3I0  Go to UniProtKB:  Q6S3I0

Entity ID: 3
Molecule	Chains	Sequence Length	Organism	Details	Image
ACETYLCHOLINE RECEPTOR DELTA SUBUNIT	C	522	Torpedo marmorata	Mutation(s): 0  Membrane Entity: Yes
UniProt
Find proteins for Q6S3H8 (Torpedo marmorata) Explore Q6S3H8  Go to UniProtKB:  Q6S3H8

Entity ID: 4
Molecule	Chains	Sequence Length	Organism	Details	Image
ACETYLCHOLINE RECEPTOR GAMMA SUBUNIT	E	488	Torpedo marmorata	Mutation(s): 0  Membrane Entity: Yes
UniProt
Find proteins for Q6S3H9 (Torpedo marmorata) Explore Q6S3H9  Go to UniProtKB:  Q6S3H9

Experimental Data & Validation

Experimental Data

• Method: ELECTRON MICROSCOPY
• Resolution: 6.20 Å
• Aggregation State: HELICAL ARRAY 
• Reconstruction Method: HELICAL 

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2012-04-12 
• Released Date: 2012-08-01 
Deposition Author(s): Unwin, N., Fujiyoshi, Y.

Revision History  

• Version 1.0: 2012-08-01
  Type: Initial release
  
• Version 1.1: 2012-09-12
  Changes: Database references
• Version 1.2: 2013-09-25
  Changes: Other
• Version 1.3: 2017-08-30
  Changes: Data collection
• Version 1.4: 2019-10-23
  Changes: Data collection, Other