3OUF

Structure of a K+ selective NaK mutant


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.55 Å
  • R-Value Free: 0.215 
  • R-Value Work: 0.200 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Tuning the ion selectivity of tetrameric cation channels by changing the number of ion binding sites.

Derebe, M.G.Sauer, D.B.Zeng, W.Alam, A.Shi, N.Jiang, Y.

(2011) Proc.Natl.Acad.Sci.USA 108: 598-602

  • DOI: 10.1073/pnas.1013636108
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Selective ion conduction across ion channel pores is central to cellular physiology. To understand the underlying principles of ion selectivity in tetrameric cation channels, we engineered a set of cation channel pores based on the nonselective NaK c ...

    Selective ion conduction across ion channel pores is central to cellular physiology. To understand the underlying principles of ion selectivity in tetrameric cation channels, we engineered a set of cation channel pores based on the nonselective NaK channel and determined their structures to high resolution. These structures showcase an ensemble of selectivity filters with a various number of contiguous ion binding sites ranging from 2 to 4, with each individual site maintaining a geometry and ligand environment virtually identical to that of equivalent sites in K(+) channel selectivity filters. Combined with single channel electrophysiology, we show that only the channel with four ion binding sites is K(+) selective, whereas those with two or three are nonselective and permeate Na(+) and K(+) equally well. These observations strongly suggest that the number of contiguous ion binding sites in a single file is the key determinant of the channel's selectivity properties and the presence of four sites in K(+) channels is essential for highly selective and efficient permeation of K(+) ions.


    Organizational Affiliation

    Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9040, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Potassium channel protein
A, B
97Bacillus cereus m1550Mutation(s): 1 
Membrane protein
mpstruc
Group: 
TRANSMEMBRANE PROTEINS: ALPHA-HELICAL
Sub Group: 
Channels: Potassium, Sodium, & Proton Ion-Selective
Protein: 
NaK channel (Na+complex)
Find proteins for C2R3K4 (Bacillus cereus m1550)
Go to UniProtKB:  C2R3K4
Small Molecules
Ligands 2 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
MPD
Query on MPD

Download SDF File 
Download CCD File 
A, B
(4S)-2-METHYL-2,4-PENTANEDIOL
C6 H14 O2
SVTBMSDMJJWYQN-YFKPBYRVSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.55 Å
  • R-Value Free: 0.215 
  • R-Value Work: 0.200 
  • Space Group: I 4
Unit Cell:
Length (Å)Angle (°)
a = 67.939α = 90.00
b = 67.939β = 90.00
c = 89.638γ = 90.00
Software Package:
Software NamePurpose
DENZOdata reduction
PDB_EXTRACTdata extraction
CNSrefinement
SCALEPACKdata scaling
HKL-2000data collection
CNSphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2011-01-12
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance
  • Version 1.2: 2017-11-08
    Type: Refinement description