Cryo-EM Structure of the Hyperpolarization-Activated Potassium Channel KAT1: Tetramer

Experimental Data Snapshot

  • Resolution: 3.50 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

wwPDB Validation   3D Report Full Report

This is version 1.2 of the entry. See complete history


Electromechanical coupling in the hyperpolarization-activated K + channel KAT1.

Clark, M.D.Contreras, G.F.Shen, R.Perozo, E.

(2020) Nature 583: 145-149

  • DOI: https://doi.org/10.1038/s41586-020-2335-4
  • Primary Citation of Related Structures:  
    6V1X, 6V1Y

  • PubMed Abstract: 

    Voltage-gated potassium (K v ) channels coordinate electrical signalling and control cell volume by gating in response to membrane depolarization or hyperpolarization. However, although voltage-sensing domains transduce transmembrane electric field changes by a common mechanism involving the outward or inward translocation of gating charges 1-3 , the general determinants of channel gating polarity remain poorly understood 4 . Here we suggest a molecular mechanism for electromechanical coupling and gating polarity in non-domain-swapped K v channels on the basis of the cryo-electron microscopy structure of KAT1, the hyperpolarization-activated K v channel from Arabidopsis thaliana. KAT1 displays a depolarized voltage sensor, which interacts with a closed pore domain directly via two interfaces and indirectly via an intercalated phospholipid. Functional evaluation of KAT1 structure-guided mutants at the sensor-pore interfaces suggests a mechanism in which direct interaction between the sensor and the C-linker hairpin in the adjacent pore subunit is the primary determinant of gating polarity. We suggest that an inward motion of the S4 sensor helix of approximately 5-7 Å can underlie a direct-coupling mechanism, driving a conformational reorientation of the C-linker and ultimately opening the activation gate formed by the S6 intracellular bundle. This direct-coupling mechanism contrasts with allosteric mechanisms proposed for hyperpolarization-activated cyclic nucleotide-gated channels 5 , and may represent an unexpected link between depolarization- and hyperpolarization-activated channels.

  • Organizational Affiliation

    Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Potassium channel KAT1
A, B, C, D
512Arabidopsis thalianaMutation(s): 0 
Gene Names: KAT1At5g46240MPL12.2
Membrane Entity: Yes 
Find proteins for Q39128 (Arabidopsis thaliana)
Explore Q39128 
Go to UniProtKB:  Q39128
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ39128
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 3.50 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 
EM Software:
TaskSoftware PackageVersion

Structure Validation

View Full Validation Report

Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)United StatesR01GM088406
National Institutes of Health/National Institute of Mental Health (NIH/NIMH)United StatesF30MH116647

Revision History  (Full details and data files)

  • Version 1.0: 2020-06-03
    Type: Initial release
  • Version 1.1: 2020-12-16
    Changes: Database references
  • Version 1.2: 2024-03-06
    Changes: Data collection, Database references