3LDC

High resolution open MthK pore structure crystallized in 100 mM K+


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.45 Å
  • R-Value Free: 0.202 
  • R-Value Work: 0.187 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Novel insights into K(+) selectivity from high-resolution structures of an open K(+) channel pore.

Ye, S.Li, Y.Jiang, Y.

(2010) Nat.Struct.Mol.Biol. 17: 1019-1023

  • DOI: 10.1038/nsmb.1865
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • K+ channels are highly selective for K+ over Na+. Here we present several crystal structures of the MthK K+ channel pore at up to 1.45-A resolution. The MthK selectivity filter maintains a conductive conformation even in the absence of K+, allowing t ...

    K+ channels are highly selective for K+ over Na+. Here we present several crystal structures of the MthK K+ channel pore at up to 1.45-A resolution. The MthK selectivity filter maintains a conductive conformation even in the absence of K+, allowing the channel to conduct Na+. The high-resolution structures, along with single-channel recordings, allow for an accurate analysis of how K+ competes with Na+ in a conductive selectivity filter. At high K+ concentrations, two K+ ions equivalently occupy the four sites in the selectivity filter, whereas at low K+/high Na+ concentrations, a single K+ ion remains bound in the selectivity filter, preferably at site 1 or site 3. This single K+ binding at low concentration effectively blocks the permeation of Na+, providing a structural basis for the anomalous mole-fraction effect, a key property of multi-ion pores.


    Organizational Affiliation

    Life Sciences Institute, Zhejiang University, Zhejiang, China. sye@zju.edu.cn




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Calcium-gated potassium channel mthK
A
82Methanothermobacter thermautotrophicus (strain ATCC 29096 / DSM 1053 / JCM 10044 / NBRC 100330 / Delta H)Mutation(s): 2 
Gene Names: mthK
Membrane protein
mpstruct
Group: 
TRANSMEMBRANE PROTEINS: ALPHA-HELICAL
Sub Group: 
Channels: Potassium, Sodium, & Proton Ion-Selective
Protein: 
MthK Potassium channel, Ca++ gated
Find proteins for O27564 (Methanothermobacter thermautotrophicus (strain ATCC 29096 / DSM 1053 / JCM 10044 / NBRC 100330 / Delta H))
Go to UniProtKB:  O27564
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
K
Query on K

Download SDF File 
Download CCD File 
A
POTASSIUM ION
K
NPYPAHLBTDXSSS-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.45 Å
  • R-Value Free: 0.202 
  • R-Value Work: 0.187 
  • Space Group: P 4 21 2
Unit Cell:
Length (Å)Angle (°)
a = 63.811α = 90.00
b = 63.811β = 90.00
c = 44.050γ = 90.00
Software Package:
Software NamePurpose
HKL-2000data scaling
HKL-2000data collection
REFMACrefinement
HKL-2000data reduction
PHASESphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

  • Deposited Date: 2010-01-12 
  • Released Date: 2010-08-11 
  • Deposition Author(s): Ye, S.

Revision History 

  • Version 1.0: 2010-08-11
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance