4FZ0

Crystal structure of acid-sensing ion channel in complex with psalmotoxin 1 at low pH


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.80 Å
  • R-Value Free: 0.231 
  • R-Value Work: 0.202 
  • R-Value Observed: 0.203 

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This is version 1.2 of the entry. See complete history


Literature

Structural plasticity and dynamic selectivity of acid-sensing ion channel-spider toxin complexes.

Baconguis, I.Gouaux, E.

(2012) Nature 489: 400-405

  • DOI: 10.1038/nature11375
  • Primary Citation of Related Structures:  
    4FZ0, 4FZ1

  • PubMed Abstract: 
  • Acid-sensing ion channels (ASICs) are voltage-independent, amiloride-sensitive channels involved in diverse physiological processes ranging from nociception to taste. Despite the importance of ASICs in physiology, we know little about the mechanism of channel activation ...

    Acid-sensing ion channels (ASICs) are voltage-independent, amiloride-sensitive channels involved in diverse physiological processes ranging from nociception to taste. Despite the importance of ASICs in physiology, we know little about the mechanism of channel activation. Here we show that psalmotoxin activates non-selective and Na(+)-selective currents in chicken ASIC1a at pH 7.25 and 5.5, respectively. Crystal structures of ASIC1a-psalmotoxin complexes map the toxin binding site to the extracellular domain and show how toxin binding triggers an expansion of the extracellular vestibule and stabilization of the open channel pore. At pH 7.25 the pore is approximately 10 Å in diameter, whereas at pH 5.5 the pore is largely hydrophobic and elliptical in cross-section with dimensions of approximately 5 by 7 Å, consistent with a barrier mechanism for ion selectivity. These studies define mechanisms for activation of ASICs, illuminate the basis for dynamic ion selectivity and provide the blueprints for new therapeutic agents.


    Organizational Affiliation

    Vollum Institute, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, Oregon 97239, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Acid-sensing ion channel 1A, B, C450Gallus gallusMutation(s): 0 
Gene Names: ASIC1ACCN2
Membrane Entity: Yes 
UniProt
Find proteins for Q1XA76 (Gallus gallus)
Explore Q1XA76 
Go to UniProtKB:  Q1XA76
Protein Feature View
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
Pi-theraphotoxin-Pc1aD [auth M], E [auth N], F [auth O]40Psalmopoeus cambridgeiMutation(s): 0 
UniProt
Find proteins for P60514 (Psalmopoeus cambridgei)
Explore P60514 
Go to UniProtKB:  P60514
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.80 Å
  • R-Value Free: 0.231 
  • R-Value Work: 0.202 
  • R-Value Observed: 0.203 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 232.29α = 90
b = 108.71β = 119.78
c = 126.36γ = 90
Software Package:
Software NamePurpose
ADSCdata collection
PHASERphasing
PHENIXrefinement
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

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Ligand Structure Quality Assessment  



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2012-08-01
    Type: Initial release
  • Version 1.1: 2012-10-03
    Changes: Database references
  • Version 1.2: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Data collection, Derived calculations, Structure summary