6HY7

Crystal structure of alpha9 nAChR extracellular domain in complex with alpha-conotoxin RgIA


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.26 Å
  • R-Value Free: 0.249 
  • R-Value Work: 0.193 
  • R-Value Observed: 0.196 

Starting Model: experimental
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Ligand Structure Quality Assessment 


This is version 1.4 of the entry. See complete history


Literature

Crystal Structure of the Monomeric Extracellular Domain of alpha 9 Nicotinic Receptor Subunit in Complex With alpha-Conotoxin RgIA: Molecular Dynamics Insights Into RgIA Binding to alpha 9 alpha 10 Nicotinic Receptors.

Zouridakis, M.Papakyriakou, A.Ivanov, I.A.Kasheverov, I.E.Tsetlin, V.Tzartos, S.Giastas, P.

(2019) Front Pharmacol 10: 474-474

  • DOI: https://doi.org/10.3389/fphar.2019.00474
  • Primary Citation of Related Structures:  
    6HY7

  • PubMed Abstract: 

    The α9 subunit of nicotinic acetylcholine receptors (nAChRs) exists mainly in heteropentameric assemblies with α10. Accumulating data indicate the presence of three different binding sites in α9α10 nAChRs: the α9(+)/α9(-), the α9(+)/α10(-), and the α10(+)/α9(-). The major role of the principal (+) side of the extracellular domain (ECD) of α9 subunit in binding of the antagonists methyllylcaconitine and α-bungarotoxin was shown previously by the crystal structures of the monomeric α9-ECD with these molecules. Here we present the 2.26-Å resolution crystal structure of α9-ECD in complex with α-conotoxin (α-Ctx) RgIA, a potential drug for chronic pain, the first structure reported for a complex between an nAChR domain and an α-Ctx. Superposition of this structure with those of other α-Ctxs bound to the homologous pentameric acetylcholine binding proteins revealed significant similarities in the orientation of bound conotoxins, despite the monomeric state of the α9-ECD. In addition, ligand-binding studies calculated a binding affinity of RgIA to the α9-ECD at the low micromolar range. Given the high identity between α9 and α10 ECDs, particularly at their (+) sides, the presented structure was used as template for molecular dynamics simulations of the ECDs of the human α9α10 nAChR in pentameric assemblies. Our results support a favorable binding of RgIA at α9(+)/α9(-) or α10(+)/α9(-) rather than the α9(+)/α10(-) interface, in accordance with previous mutational and functional data.


  • Organizational Affiliation

    Department of Neurobiology, Hellenic Pasteur Institute, Athens, Greece.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Neuronal acetylcholine receptor subunit alpha-9218Homo sapiensMutation(s): 0 
Gene Names: CHRNA9NACHRA9
UniProt & NIH Common Fund Data Resources
Find proteins for Q9UGM1 (Homo sapiens)
Explore Q9UGM1 
Go to UniProtKB:  Q9UGM1
PHAROS:  Q9UGM1
GTEx:  ENSG00000174343 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ9UGM1
Glycosylation
Glycosylation Sites: 2Go to GlyGen: Q9UGM1-1
Sequence Annotations
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  • Reference Sequence

Find similar proteins by:  Sequence   |   3D Structure  

Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
Alpha-conotoxin RgIA13Conus regiusMutation(s): 0 
UniProt
Find proteins for P0C1D0 (Conus regius)
Explore P0C1D0 
Go to UniProtKB:  P0C1D0
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP0C1D0
Sequence Annotations
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  • Reference Sequence
Small Molecules
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.26 Å
  • R-Value Free: 0.249 
  • R-Value Work: 0.193 
  • R-Value Observed: 0.196 
  • Space Group: P 21 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 63.646α = 90
b = 82.53β = 90
c = 49.474γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
XDSdata reduction
XDSdata scaling
PHASERphasing

Structure Validation

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Ligand Structure Quality Assessment 


Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2019-05-22
    Type: Initial release
  • Version 1.1: 2019-06-05
    Changes: Data collection, Database references
  • Version 1.2: 2019-08-21
    Changes: Data collection
  • Version 1.3: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Data collection, Derived calculations, Structure summary
  • Version 1.4: 2024-01-24
    Changes: Data collection, Database references, Refinement description, Structure summary