3K6N

Crystal structure of the S225E mutant Kir3.1 cytoplasmic pore domain


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 0.266 
  • R-Value Work: 0.254 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Physical determinants of strong voltage sensitivity of K(+) channel block.

Xu, Y.Shin, H.G.Szep, S.Lu, Z.

(2009) Nat Struct Mol Biol 16: 1252-1258

  • DOI: 10.1038/nsmb.1717
  • Structures With Same Primary Citation

  • PubMed Abstract: 
  • Strong voltage sensitivity of inward-rectifier K(+) (Kir) channels has been hypothesized to arise primarily from an intracellular blocker displacing up to five K(+) ions from the wide, intracellular part of the ion conduction pore outwardly across th ...

    Strong voltage sensitivity of inward-rectifier K(+) (Kir) channels has been hypothesized to arise primarily from an intracellular blocker displacing up to five K(+) ions from the wide, intracellular part of the ion conduction pore outwardly across the narrow ion-selectivity filter. The validity of this hypothesis depends on two assumptions: (i) that five ion sites are located intracellular to the filter and (ii) that the blocker can force essentially unidirectional K(+) movement in a pore region generally wider than the combined dimensions of the blocker plus a K(+) ion. Here we present a crystal structure of the cytoplasmic portion of a Kir channel with five ions bound and demonstrate that a constriction near the intracellular end of the pore, acting as a gasket, prevents K(+) ions from bypassing the blocker. This heretofore unrecognized 'gasket' ensures that the blocker can effectively displace K(+) ions across the selectivity filter to generate exceedingly strong voltage sensitivity.


    Organizational Affiliation

    Department of Physiology, Howard Hughes Medical Institute, University of Pennsylvania, Philadelphia, Pennsylvania, USA.



Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
G protein-activated inward rectifier potassium channel 1
A
207Mus musculusMutation(s): 1 
Gene Names: Girk1Kcnj3
Membrane protein
Mpstruc
Group: 
TRANSMEMBRANE PROTEINS: ALPHA-HELICAL
Sub Group: 
Channels: Potassium, Sodium, & Proton Ion-Selective
Protein: 
Kir3.1 cytoplasmic domain
Find proteins for P63250 (Mus musculus)
Go to UniProtKB:  P63250
NIH Common Fund Data Resources
IMPC  MGI:104742
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
NA
Query on NA

Download CCD File 
A
SODIUM ION
Na
FKNQFGJONOIPTF-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 0.266 
  • R-Value Work: 0.254 
  • Space Group: P 4 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 77.455α = 90
b = 77.455β = 90
c = 86.723γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
AMoREphasing
CNSrefinement
PDB_EXTRACTdata extraction
HKL-2000data collection
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2009-11-17
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2017-08-02
    Changes: Refinement description, Source and taxonomy
  • Version 1.3: 2017-11-01
    Changes: Refinement description