Biological Assembly 1  

 3D View: Structure

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Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Hetero 5-mer - A2BCD Pseudo Symmetry: Cyclic - C5  (3D View)
Pseudo Stoichiometry: Homo 5-mer -A5 

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 278066.91 
• Atom Count: 14924 
• Residue Count: 2425 
• Unique protein chains: 4

4AQ5

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

• DOI: 10.2210/pdb4AQ5/pdb
• EMDataBank: EMD-2071

• Classification: MEMBRANE PROTEIN
• Organism(s): Torpedo marmorata


• 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: 6.2 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:  
  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: 

MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK. [e-mail]

Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details
ACETYLCHOLINE RECEPTOR SUBUNIT ALPHA	A, D	461	Torpedo marmorata	Mutation(s): 0  Gene Names: CHRNA1
Membrane protein mpstruct	Group:  TRANSMEMBRANE PROTEINS: ALPHA-HELICAL		Sub Group:  Cys-Loop Receptor Family	Protein:  Nicotinic Acetylcholine Receptor Pore (closed state)
Find proteins for P02711 (Torpedo marmorata) Go to Gene View: CHRNA1 Go to UniProtKB:  P02711

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details
ACETYLCHOLINE RECEPTOR BETA SUBUNIT	B	493	Torpedo marmorata	Mutation(s): 0
Membrane protein mpstruct	Group:  TRANSMEMBRANE PROTEINS: ALPHA-HELICAL		Sub Group:  Cys-Loop Receptor Family	Protein:  Nicotinic Acetylcholine Receptor Pore (closed state)
Find proteins for Q6S3I0 (Torpedo marmorata) Go to UniProtKB:  Q6S3I0

Entity ID: 3
Molecule	Chains	Sequence Length	Organism	Details
ACETYLCHOLINE RECEPTOR DELTA SUBUNIT	C	522	Torpedo marmorata	Mutation(s): 0
Membrane protein mpstruct	Group:  TRANSMEMBRANE PROTEINS: ALPHA-HELICAL		Sub Group:  Cys-Loop Receptor Family	Protein:  Nicotinic Acetylcholine Receptor Pore (closed state)
Find proteins for Q6S3H8 (Torpedo marmorata) Go to UniProtKB:  Q6S3H8

Entity ID: 4
Molecule	Chains	Sequence Length	Organism	Details
ACETYLCHOLINE RECEPTOR GAMMA SUBUNIT	E	488	Torpedo marmorata	Mutation(s): 0
Membrane protein mpstruct	Group:  TRANSMEMBRANE PROTEINS: ALPHA-HELICAL		Sub Group:  Cys-Loop Receptor Family	Protein:  Nicotinic Acetylcholine Receptor Pore (closed state)
Find proteins for Q6S3H9 (Torpedo marmorata) Go to UniProtKB:  Q6S3H9

Experimental Data & Validation

Experimental Data

• Method: ELECTRON MICROSCOPY
• Resolution: 6.2 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
  Type: Database references
• Version 1.2: 2013-09-25
  Type: Other
• Version 1.3: 2017-08-30
  Type: Data collection