KCSA potassium channel with TBA (tetrabutylammonium) and potassium

Experimental Data Snapshot

  • Resolution: 2.80 Å
  • R-Value Free: 0.322 
  • R-Value Work: 0.298 
  • R-Value Observed: 0.320 

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This is version 1.4 of the entry. See complete history


Potassium channel receptor site for the inactivation gate and quaternary amine inhibitors

Zhou, M.Morais-Cabral, J.H.Mann, S.MacKinnon, R.

(2001) Nature 411: 657-661

  • DOI: https://doi.org/10.1038/35079500
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    Many voltage-dependent K+ channels open when the membrane is depolarized and then rapidly close by a process called inactivation. Neurons use inactivating K+ channels to modulate their firing frequency. In Shaker-type K+ channels, the inactivation gate, which is responsible for the closing of the channel, is formed by the channel's cytoplasmic amino terminus. Here we show that the central cavity and inner pore of the K+ channel form the receptor site for both the inactivation gate and small-molecule inhibitors. We propose that inactivation occurs by a sequential reaction in which the gate binds initially to the cytoplasmic channel surface and then enters the pore as an extended peptide. This mechanism accounts for the functional properties of K+ channel inactivation and indicates that the cavity may be the site of action for certain drugs that alter cation channel function.

  • Organizational Affiliation

    Department of Molecular Biophysics and Biochemistry, Yale University, 260 Whitney Avenue, New Haven, Connecticut 06520, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
A, B, C, D
125Streptomyces lividansMutation(s): 1 
Membrane Entity: Yes 
Find proteins for P0A334 (Streptomyces lividans)
Explore P0A334 
Go to UniProtKB:  P0A334
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP0A334
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.80 Å
  • R-Value Free: 0.322 
  • R-Value Work: 0.298 
  • R-Value Observed: 0.320 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 128.9α = 90
b = 67.4β = 125.3
c = 112γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2001-06-13
    Type: Initial release
  • Version 1.1: 2008-04-27
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2021-10-27
    Changes: Database references, Derived calculations
  • Version 1.4: 2023-08-16
    Changes: Data collection, Refinement description