2BOB

Potassium channel KcsA-Fab complex in thallium with tetrabutylammonium (TBA)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.76 Å
  • R-Value Free: 0.251 
  • R-Value Work: 0.220 
  • R-Value Observed: 0.222 

Starting Model: experimental
View more details

wwPDB Validation   3D Report Full Report


Ligand Structure Quality Assessment 


This is version 1.4 of the entry. See complete history


Literature

Structural Basis of Tea Blockade in a Model Potassium Channel

Lenaeus, M.J.Vamvouka, M.Focia, P.J.Gross, A.

(2005) Nat Struct Mol Biol 12: 454

  • DOI: https://doi.org/10.1038/nsmb929
  • Primary Citation of Related Structures:  
    2BOB, 2BOC

  • PubMed Abstract: 

    Potassium channels catalyze the selective transfer of potassium across the cell membrane and are essential for setting the resting potential in cells, controlling heart rate and modulating the firing pattern in neurons. Tetraethylammonium (TEA) blocks ion conduction through potassium channels in a voltage-dependent manner from both sides of the membrane. Here we show the structural basis of TEA blockade by cocrystallizing the prokaryotic potassium channel KcsA with two selective TEA analogs. TEA binding at both sites alters ion occupancy in the selectivity filter; these findings underlie the mutual destabilization and voltage-dependence of TEA blockade. We propose that TEA blocks potassium channels by acting as a potassium analog at the dehydration transition step during permeation.


  • Organizational Affiliation

    Department of Molecular Pharmacology and Biological Chemistry, Northwestern University Medical School, 303 East Chicago Avenue, Chicago, Illinois 60611, USA.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
ANTIBODY FAB FRAGMENT HEAVY CHAIN219Mus musculusMutation(s): 0 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
Sequence Annotations
Expand
  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
ANTIBODY FAB FRAGMENT LIGHT CHAIN212Mus musculusMutation(s): 0 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
Sequence Annotations
Expand
  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 3
MoleculeChains Sequence LengthOrganismDetailsImage
POTASSIUM CHANNEL KCSA124Streptomyces lividansMutation(s): 1 
Membrane Entity: Yes 
UniProt
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
Expand
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.76 Å
  • R-Value Free: 0.251 
  • R-Value Work: 0.220 
  • R-Value Observed: 0.222 
  • Space Group: I 4
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 155.267α = 90
b = 155.267β = 90
c = 75.555γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
XDSdata reduction
XDSdata scaling
CNSphasing

Structure Validation

View Full Validation Report



Ligand Structure Quality Assessment 


Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2005-04-27
    Type: Initial release
  • Version 1.1: 2011-05-08
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2017-07-12
    Changes: Derived calculations
  • Version 1.4: 2023-12-13
    Changes: Data collection, Database references, Derived calculations, Other, Refinement description