Human K2P4.1 (TRAAK) potassium channel, G124I mutant

Experimental Data Snapshot

  • Resolution: 3.30 Å
  • R-Value Free: 0.323 
  • R-Value Work: 0.291 
  • R-Value Observed: 0.293 

wwPDB Validation   3D Report Full Report

This is version 1.3 of the entry. See complete history


Transmembrane Helix Straightening and Buckling Underlies Activation of Mechanosensitive and Thermosensitive K2P Channels.

Lolicato, M.Riegelhaupt, P.M.Arrigoni, C.Clark, K.A.Minor, D.L.

(2014) Neuron 84: 1198-1212

  • DOI: https://doi.org/10.1016/j.neuron.2014.11.017
  • Primary Citation of Related Structures:  
    4RUE, 4RUF

  • PubMed Abstract: 

    Mechanical and thermal activation of ion channels is central to touch, thermosensation, and pain. The TRAAK/TREK K(2P) potassium channel subfamily produces background currents that alter neuronal excitability in response to pressure, temperature, signaling lipids, and anesthetics. How such diverse stimuli control channel function is unclear. Here we report structures of K(2P)4.1 (TRAAK) bearing C-type gate-activating mutations that reveal a tilting and straightening of the M4 inner transmembrane helix and a buckling of the M2 transmembrane helix. These conformational changes move M4 in a direction opposite to that in classical potassium channel activation mechanisms and open a passage lateral to the pore that faces the lipid bilayer inner leaflet. Together, our findings uncover a unique aspect of K(2P) modulation, indicate a means for how the K(2P) C-terminal cytoplasmic domain affects the C-type gate which lies ∼40Å away, and suggest how lipids and bilayer inner leaflet deformations may gate the channel.

  • Organizational Affiliation

    Cardiovascular Research Institute, University of California, San Francisco, San Francisco, California 93858-2330, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Potassium channel subfamily K member 4
A, B
309Homo sapiensMutation(s): 3 
Gene Names: KCNK4TRAAK
Membrane Entity: Yes 
UniProt & NIH Common Fund Data Resources
Find proteins for Q9NYG8 (Homo sapiens)
Explore Q9NYG8 
Go to UniProtKB:  Q9NYG8
GTEx:  ENSG00000182450 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ9NYG8
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 3.30 Å
  • R-Value Free: 0.323 
  • R-Value Work: 0.291 
  • R-Value Observed: 0.293 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 87.49α = 90
b = 118.697β = 90
c = 128.701γ = 90
Software Package:
Software NamePurpose
Blu-Icedata collection
XDSdata reduction
Aimlessdata scaling

Structure Validation

View Full Validation Report

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2014-12-17
    Type: Initial release
  • Version 1.1: 2015-01-07
    Changes: Database references
  • Version 1.2: 2017-11-22
    Changes: Refinement description
  • Version 1.3: 2023-09-20
    Changes: Data collection, Database references, Derived calculations, Refinement description