3E86

High resolution Crystal Structure of the open NaK channel pore


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.6 Å
  • R-Value Free: 0.242 
  • R-Value Work: 0.212 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

High-resolution structure of the open NaK channel

Alam, A.Jiang, Y.

(2009) Nat.Struct.Mol.Biol. 16: 30-34

  • DOI: 10.1038/nsmb.1531

  • PubMed Abstract: 
  • We report the crystal structure of the nonselective cation channel NaK from Bacillus cereus at a resolution of 1.6 A. The structure reveals the intracellular gate in an open state, as opposed to the closed form reported previously, making NaK the onl ...

    We report the crystal structure of the nonselective cation channel NaK from Bacillus cereus at a resolution of 1.6 A. The structure reveals the intracellular gate in an open state, as opposed to the closed form reported previously, making NaK the only channel for which the three-dimensional structures of both conformations are known. Channel opening follows a conserved mechanism of inner helix bending using a flexible glycine residue, the gating hinge, seen in MthK and most other tetrameric cation channels. Additionally, distinct inter and intrasubunit rearrangements involved in channel gating are seen and characterized for the first time along with inner helix twisting motions. Furthermore, we identify a residue deeper within the cavity of the channel pore, Phe92, which is likely to form a constriction point within the open pore, restricting ion flux through the channel. Mutating this residue to alanine causes a subsequent increase in ion-conduction rates as measured by (86)Rb flux assays. The structures of both the open and closed conformations of the NaK channel correlate well with those of equivalent K(+) channel conformations, namely MthK and KcsA, respectively.


    Organizational Affiliation

    Department of Physiology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9040, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Potassium channel protein
A, B
96Bacillus cereus (strain ATCC 14579 / DSM 31 / JCM 2152 / NBRC 15305 / NCIMB 9373 / NRRL B-3711)Mutation(s): 0 
Membrane protein
mpstruct
Group: 
TRANSMEMBRANE PROTEINS: ALPHA-HELICAL
Sub Group: 
Channels: Potassium, Sodium, & Proton Ion-Selective
Protein: 
NaK channel (Na+complex)
Find proteins for Q81HW2 (Bacillus cereus (strain ATCC 14579 / DSM 31 / JCM 2152 / NBRC 15305 / NCIMB 9373 / NRRL B-3711))
Go to UniProtKB:  Q81HW2
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
NA
Query on NA

Download SDF File 
Download CCD File 
A, B
SODIUM ION
Na
FKNQFGJONOIPTF-UHFFFAOYSA-N
 Ligand Interaction
CA
Query on CA

Download SDF File 
Download CCD File 
A
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
CS
Query on CS

Download SDF File 
Download CCD File 
A, B
CESIUM ION
Cs
NCMHKCKGHRPLCM-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: 1.6 Å
  • R-Value Free: 0.242 
  • R-Value Work: 0.212 
  • Space Group: I 4
Unit Cell:
Length (Å)Angle (°)
a = 68.030α = 90.00
b = 68.030β = 90.00
c = 89.264γ = 90.00
Software Package:
Software NamePurpose
PDB_EXTRACTdata extraction
HKL-2000data reduction
DENZOdata reduction
MOLREPphasing
CNSrefinement
SCALEPACKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

  • Deposited Date: 2008-08-19 
  • Released Date: 2008-12-23 
  • Deposition Author(s): Jiang, Y., Alam, A.

Revision History 

  • Version 1.0: 2008-12-23
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance
  • Version 1.2: 2011-11-16
    Type: Atomic model
  • Version 1.3: 2017-10-25
    Type: Refinement description