2DWE

Crystal structure of KcsA-FAB-TBA complex in Rb+


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Free: 0.266 
  • R-Value Work: 0.230 
  • R-Value Observed: 0.245 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Crystallographic Study of the Tetrabutylammonium Block to the KcsA K(+) Channel

Yohannan, S.Hu, Y.Zhou, Y.

(2007) J Mol Biol 366: 806-814

  • DOI: 10.1016/j.jmb.2006.11.081
  • Structures With Same Primary Citation

  • PubMed Abstract: 
  • K(+) channels play essential roles in regulating membrane excitability of many diverse cell types by selectively conducting K(+) ions through their pores. Many diverse molecules can plug the pore and modulate the K(+) current. Quaternary ammonium (QA ...

    K(+) channels play essential roles in regulating membrane excitability of many diverse cell types by selectively conducting K(+) ions through their pores. Many diverse molecules can plug the pore and modulate the K(+) current. Quaternary ammonium (QA) ions are a class of pore blockers that have been used for decades by biophysicists to probe the pore, leading to important insights into the structure-function relation of K(+) channels. However, many key aspects of the QA-blocking mechanisms remain unclear to date, and understanding these questions requires high resolution structural information. Here, we address the question of whether intracellular QA blockade causes conformational changes of the K(+) channel selectivity filter. We have solved the structures of the KcsA K(+) channel in complex with tetrabutylammonium (TBA) and tetrabutylantimony (TBSb) under various ionic conditions. Our results demonstrate that binding of TBA or TBSb causes no significant change in the KcsA structure at high concentrations of permeant ions. We did observe the expected conformational change of the filter at low concentration of K(+), but this change appears to be independent of TBA or TBSb blockade.


    Organizational Affiliation

    Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT 06520, USA.



Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
ANTIBODY FAB HEAVY CHAIN
A
219Mus musculusMutation(s): 0 
Protein Feature View
  • Reference Sequence

Find similar proteins by: Sequence  |  Structure

Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
ANTIBODY FAB LIGHT CHAIN
B
212Mus musculusMutation(s): 0 
Protein Feature View
  • Reference Sequence

Find similar proteins by: Sequence  |  Structure

Entity ID: 3
MoleculeChainsSequence LengthOrganismDetails
Voltage-gated potassium channel
C
103Streptomyces lividansMutation(s): 1 
Gene Names: kcsAskc1
Find proteins for P0A334 (Streptomyces lividans)
Go to UniProtKB:  P0A334
Protein Feature View
  • Reference Sequence
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
L2C
Query on L2C

Download CCD File 
C
(2S)-3-HYDROXY-2-(NONANOYLOXY)PROPYL LAURATE
C24 H46 O5
MYFVXYUACRBWGD-QFIPXVFZSA-N
 Ligand Interaction
TBA
Query on TBA

Download CCD File 
C
TETRABUTYLAMMONIUM ION
C16 H36 N
DZLFLBLQUQXARW-UHFFFAOYSA-N
 Ligand Interaction
F09
Query on F09

Download CCD File 
C
NONAN-1-OL
C9 H20 O
ZWRUINPWMLAQRD-UHFFFAOYSA-N
 Ligand Interaction
RB
Query on RB

Download CCD File 
C
RUBIDIUM ION
Rb
NCCSSGKUIKYAJD-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Free: 0.266 
  • R-Value Work: 0.230 
  • R-Value Observed: 0.245 
  • Space Group: I 4
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 154.56α = 90
b = 154.56β = 90
c = 75.813γ = 90
Software Package:
Software NamePurpose
CBASSdata collection
CNSrefinement
HKL-2000data reduction
SCALEPACKdata scaling
CNSphasing

Structure Validation

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Entry History 

Deposition Data

  • Deposited Date: 2006-08-10 
  • Released Date: 2007-02-20 
  • Deposition Author(s): Yohannan, S., Zhou, Y.

Revision History 

  • Version 1.0: 2007-02-20
    Type: Initial release
  • Version 1.1: 2008-04-30
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Derived calculations, Version format compliance