1JVM

KCSA POTASSIUM CHANNEL WITH TBA (TETRABUTYLAMMONIUM) AND RUBIDIUM


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.8 Å
  • R-Value Free: 0.302 
  • R-Value Work: 0.281 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Energetic optimization of ion conduction rate by the K+ selectivity filter.

Morais-Cabral, J.H.Zhou, Y.MacKinnon, R.

(2001) Nature 414: 37-42

  • DOI: 10.1038/35102000

  • PubMed Abstract: 
  • The K+ selectivity filter catalyses the dehydration, transfer and rehydration of a K+ ion in about ten nanoseconds. This physical process is central to the production of electrical signals in biology. Here we show how nearly diffusion-limited rates a ...

    The K+ selectivity filter catalyses the dehydration, transfer and rehydration of a K+ ion in about ten nanoseconds. This physical process is central to the production of electrical signals in biology. Here we show how nearly diffusion-limited rates are achieved, by analysing ion conduction and the corresponding crystallographic ion distribution in the selectivity filter of the KcsA K+ channel. Measurements with K+ and its slightly larger analogue, Rb+, lead us to conclude that the selectivity filter usually contains two K+ ions separated by one water molecule. The two ions move in a concerted fashion between two configurations, K+-water-K+-water (1,3 configuration) and water-K+-water-K+ (2,4 configuration), until a third ion enters, displacing the ion on the opposite side of the queue. For K+, the energy difference between the 1,3 and 2,4 configurations is close to zero, the condition of maximum conduction rate. The energetic balance between these configurations is a clear example of evolutionary optimization of protein function.


    Organizational Affiliation

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




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Voltage-gated potassium channel
A, B, C, D
125Streptomyces lividansMutation(s): 2 
Gene Names: kcsA (skc1)
Find proteins for P0A334 (Streptomyces lividans)
Go to UniProtKB:  P0A334
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
TBA
Query on TBA

Download SDF File 
Download CCD File 
A
TETRABUTYLAMMONIUM ION
C16 H36 N
DZLFLBLQUQXARW-UHFFFAOYSA-N
 Ligand Interaction
RB
Query on RB

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

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.8 Å
  • R-Value Free: 0.302 
  • R-Value Work: 0.281 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 129.800α = 90.00
b = 69.400β = 125.60
c = 112.700γ = 90.00
Software Package:
Software NamePurpose
CNSphasing
DENZOdata reduction
CNSrefinement
SCALEPACKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2001-12-05
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance