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 

wwPDB Validation 3D Report Full Report


This is version 1.3 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: 10.1038/nsmb929
  • Primary Citation of Related Structures:  

  • 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) block ...

    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: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
ANTIBODY FAB FRAGMENT HEAVY CHAIN
A
219N/A
Protein Feature View is not available: No corresponding UniProt sequence found.
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
ANTIBODY FAB FRAGMENT LIGHT CHAIN
B
212N/A
Protein Feature View is not available: No corresponding UniProt sequence found.
Entity ID: 3
MoleculeChainsSequence LengthOrganismDetails
POTASSIUM CHANNEL KCSA
C
124Streptomyces lividansMutations: C90L
Gene Names: kcsA (skc1)
Membrane protein
mpstruct		Group: 
TRANSMEMBRANE PROTEINS: ALPHA-HELICAL		Sub Group: 
Channels: Potassium, Sodium, & Proton Ion-Selective		Protein: 
KcsA Potassium channel, H+ gated
Find proteins for P0A334 (Streptomyces lividans)
Go to UniProtKB:  P0A334
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
TBA
Query on TBA
Download SDF File 
Download CCD File 
C
TETRABUTYLAMMONIUM ION
C16 H36 N
DZLFLBLQUQXARW-UHFFFAOYSA-N
 Ligand Interaction
TL
Query on TL
Download SDF File 
Download CCD File 
C
THALLIUM (I) ION
Tl
ZLUSCZLCHQSJRU-UHFFFAOYSA-N
 Ligand Interaction
CO
Query on CO
Download SDF File 
Download CCD File 
C
COBALT (II) ION
Co
XLJKHNWPARRRJB-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.76 Å
  • R-Value Free: 0.251 
  • R-Value Work: 0.220 
  • Space Group: I 4
Unit Cell:
Length (Å)Angle (°)
a = 155.267α = 90.00
b = 155.267β = 90.00
c = 75.555γ = 90.00
Software Package:
Software NamePurpose
XDSdata reduction
CNSphasing
REFMACrefinement
XDSdata scaling

Structure Validation

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View more in-depth experimental data

Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2005-04-27
    Type: Initial release
  • Version 1.1: 2011-05-08
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2017-07-12
    Type: Derived calculations