8QQM

nicotinic acetylcholine receptor in intact synaptic membrane


Experimental Data Snapshot

  • Method: ELECTRON MICROSCOPY
  • Resolution: 4.70 Å
  • Aggregation State: HELICAL ARRAY 
  • Reconstruction Method: SINGLE PARTICLE 

Starting Model: experimental
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wwPDB Validation   3D Report Full Report


This is version 1.0 of the entry. See complete history


Literature

Influence of lipid bilayer on the structure of the muscle-type nicotinic acetylcholine receptor.

Unwin, N.

(2024) Proc Natl Acad Sci U S A 121: e2319913121-e2319913121

  • DOI: https://doi.org/10.1073/pnas.2319913121
  • Primary Citation of Related Structures:  
    8QQM

  • PubMed Abstract: 

    The muscle-type nicotinic acetylcholine receptor is a transmitter-gated ion channel residing in the plasma membrane of electrocytes and striated muscle cells. It is present predominantly at synaptic junctions, where it effects rapid depolarization of the postsynaptic membrane in response to acetylcholine released into the synaptic cleft. Previously, cryo-EM of intact membrane from Torpedo revealed that the lipid bilayer surrounding the junctional receptor has a uniquely asymmetric and ordered structure, due to a high concentration of cholesterol. It is now shown that this special lipid environment influences the transmembrane (TM) folding of the protein. All five submembrane MX helices of the membrane-intact junctional receptor align parallel to the surface of the cholesterol-ordered lipids in the inner leaflet of the bilayer; also, the TM helices in the outer leaflet are splayed apart. However in the structure obtained from the same protein after extraction and incorporation in nanodiscs, the MX helices do not align to a planar surface, and the TM helices arrange compactly in the outer leaflet. Realignment of the MX helices of the nanodisc-solved structure to a planar surface converts their adjoining TM helices into an obligatory splayed configuration, characteristic of the junctional receptor. Thus, the form of the receptor sustained by the special lipid environment of the synaptic junction is the one that mediates fast synaptic transmission; whereas, the nanodisc-embedded protein may be like the extrajunctional form, existing in a disordered lipid environment.


  • Organizational Affiliation

    Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom.


Macromolecules
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Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Acetylcholine receptor subunit alpha
A, D
437Tetronarce californicaMutation(s): 0 
Membrane Entity: Yes 
UniProt
Find proteins for P02710 (Tetronarce californica)
Explore P02710 
Go to UniProtKB:  P02710
Entity Groups  
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UniProt GroupP02710
Sequence Annotations
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  • Reference Sequence
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Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
Acetylcholine receptor subunit delta501Tetronarce californicaMutation(s): 0 
Membrane Entity: Yes 
UniProt
Find proteins for P02718 (Tetronarce californica)
Explore P02718 
Go to UniProtKB:  P02718
Entity Groups  
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UniProt GroupP02718
Sequence Annotations
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  • Reference Sequence
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Entity ID: 3
MoleculeChains Sequence LengthOrganismDetailsImage
Acetylcholine receptor subunit beta469Tetronarce californicaMutation(s): 0 
Membrane Entity: Yes 
UniProt
Find proteins for P02712 (Tetronarce californica)
Explore P02712 
Go to UniProtKB:  P02712
Entity Groups  
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UniProt GroupP02712
Sequence Annotations
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  • Reference Sequence
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Entity ID: 4
MoleculeChains Sequence LengthOrganismDetailsImage
Acetylcholine receptor subunit gamma489Tetronarce californicaMutation(s): 0 
Membrane Entity: Yes 
UniProt
Find proteins for P02714 (Tetronarce californica)
Explore P02714 
Go to UniProtKB:  P02714
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP02714
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: ELECTRON MICROSCOPY
  • Resolution: 4.70 Å
  • Aggregation State: HELICAL ARRAY 
  • Reconstruction Method: SINGLE PARTICLE 
EM Software:
TaskSoftware PackageVersion
RECONSTRUCTIONRELION2.1
MODEL REFINEMENTDireX

Structure Validation

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Entry History & Funding Information

Deposition Data

  • Released Date: 2024-05-08 
  • Deposition Author(s): Unwin, N.

Funding OrganizationLocationGrant Number
UK Research and Innovation (UKRI)United KingdomMC_U105184294

Revision History  (Full details and data files)

  • Version 1.0: 2024-05-08
    Type: Initial release