3IFX

Crystal structure of the Spin-labeled KcsA mutant V48R1


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.56 Å
  • R-Value Free: 0.302 
  • R-Value Work: 0.271 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Electron Spin-Echo Envelope Modulation (ESEEM) Reveals Water and Phosphate Interactions with the KcsA Potassium Channel

Cieslak, J.A.Focia, P.J.Gross, A.

(2010) Biochemistry 49: 1486-1494

  • DOI: 10.1021/bi9016523

  • PubMed Abstract: 
  • Electron spin-echo envelope modulation (ESEEM) spectroscopy is a well-established technique for the study of naturally occurring paramagnetic metal centers. The technique has been used to study copper complexes, hemes, enzyme mechanisms, micellar wat ...

    Electron spin-echo envelope modulation (ESEEM) spectroscopy is a well-established technique for the study of naturally occurring paramagnetic metal centers. The technique has been used to study copper complexes, hemes, enzyme mechanisms, micellar water content, and water permeation profiles in membranes, among other applications. In the present study, we combine ESEEM spectroscopy with site-directed spin labeling (SDSL) and X-ray crystallography in order to evaluate the technique's potential as a structural tool to describe the native environment of membrane proteins. Using the KcsA potassium channel as a model system, we demonstrate that deuterium ESEEM can detect water permeation along the lipid-exposed surface of the KcsA outer helix. We further demonstrate that (31)P ESEEM is able to identify channel residues that interact with the phosphate headgroup of the lipid bilayer. In combination with X-ray crystallography, the (31)P data may be used to define the phosphate interaction surface of the protein. The results presented here establish ESEEM as a highly informative technique for SDSL studies of membrane proteins.


    Organizational Affiliation

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




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Voltage-gated potassium channel
A, B, C, D
129Streptomyces lividansMutation(s): 1 
Gene Names: kcsA (skc1)
Find proteins for P0A334 (Streptomyces lividans)
Go to UniProtKB:  P0A334
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
K
Query on K

Download SDF File 
Download CCD File 
A, B
POTASSIUM ION
K
NPYPAHLBTDXSSS-UHFFFAOYSA-N
 Ligand Interaction
TBA
Query on TBA

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

Download SDF File 
Download CCD File 
A, B, C, D
S-[(1-oxyl-2,2,5,5-tetramethyl-2,5-dihydro-1H-pyrrol-3-yl)methyl] methanesulfonothioate
MTSL
C10 H18 N O3 S2
MXZPGYFBZHBAQM-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.56 Å
  • R-Value Free: 0.302 
  • R-Value Work: 0.271 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 130.970α = 90.00
b = 76.630β = 125.83
c = 112.970γ = 90.00
Software Package:
Software NamePurpose
MOSFLMdata reduction
PHASERphasing
SCALAdata scaling
REFMACrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2010-02-09
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance
  • Version 1.2: 2011-07-27
    Type: Advisory, Non-polymer description, Refinement description