3UKN

Structure of the C-linker/CNBHD of zELK channels in C 2 2 21 space group


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.20 Å
  • R-Value Free: 0.254 
  • R-Value Work: 0.212 
  • R-Value Observed: 0.215 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Structure of the carboxy-terminal region of a KCNH channel.

Brelidze, T.I.Carlson, A.E.Sankaran, B.Zagotta, W.N.

(2012) Nature 481: 530-533

  • DOI: 10.1038/nature10735
  • Primary Citation of Related Structures:  
    3UKT, 3UKV, 3UKN

  • PubMed Abstract: 
  • The KCNH family of ion channels, comprising ether-à-go-go (EAG), EAG-related gene (ERG), and EAG-like (ELK) K(+)-channel subfamilies, is crucial for repolarization of the cardiac action potential, regulation of neuronal excitability and proliferation of tumour cells ...

    The KCNH family of ion channels, comprising ether-à-go-go (EAG), EAG-related gene (ERG), and EAG-like (ELK) K(+)-channel subfamilies, is crucial for repolarization of the cardiac action potential, regulation of neuronal excitability and proliferation of tumour cells. The carboxy-terminal region of KCNH channels contains a cyclic-nucleotide-binding homology domain (CNBHD) and C-linker that couples the CNBHD to the pore. The C-linker/CNBHD is essential for proper function and trafficking of ion channels in the KCNH family. However, despite the importance of the C-linker/CNBHD for the function of KCNH channels, the structural basis of ion-channel regulation by the C-linker/CNBHD is unknown. Here we report the crystal structure of the C-linker/CNBHD of zebrafish ELK channels at 2.2-Å resolution. Although the overall structure of the C-linker/CNBHD of ELK channels is similar to the cyclic-nucleotide-binding domain (CNBD) structure of the related hyperpolarization-activated cyclic-nucleotide-modulated (HCN) channels, there are marked differences. Unlike the CNBD of HCN, the CNBHD of ELK displays a negatively charged electrostatic profile that explains the lack of binding and regulation of KCNH channels by cyclic nucleotides. Instead of cyclic nucleotide, the binding pocket is occupied by a short β-strand. Mutations of the β-strand shift the voltage dependence of activation to more depolarized voltages, implicating the β-strand as an intrinsic ligand for the CNBHD of ELK channels. In both ELK and HCN channels the C-linker is the site of virtually all of the intersubunit interactions in the C-terminal region. However, in the zebrafish ELK structure there is a reorientation in the C-linker so that the subunits form dimers instead of tetramers, as observed in HCN channels. These results provide a structural framework for understanding the regulation of ion channels in the KCNH family by the C-linker/CNBHD and may guide the design of specific drugs.


    Organizational Affiliation

    Department of Physiology and Biophysics, University of Washington School of Medicine, Box 357290, Seattle, Washington 98195-7290, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Novel protein similar to vertebrate potassium voltage-gated channel, subfamily H (Eag-related) familyA, B, C212Danio rerioMutation(s): 0 
Gene Names: CH211-11O22.2-001ELKkcnh3
Find proteins for A8WHX9 (Danio rerio)
Explore A8WHX9 
Go to UniProtKB:  A8WHX9
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.20 Å
  • R-Value Free: 0.254 
  • R-Value Work: 0.212 
  • R-Value Observed: 0.215 
  • Space Group: C 2 2 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 57.98α = 90
b = 95.48β = 90
c = 241.24γ = 90
Software Package:
Software NamePurpose
BOSdata collection
PHASERphasing
PHENIXrefinement
MOSFLMdata reduction
SCALAdata scaling

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

  • Deposited Date: 2011-11-09 
  • Released Date: 2012-01-04 
  • Deposition Author(s): Brelidze, T.I.

Revision History  (Full details and data files)

  • Version 1.0: 2012-01-04
    Type: Initial release
  • Version 1.1: 2012-01-25
    Changes: Database references
  • Version 1.2: 2012-02-01
    Changes: Database references
  • Version 1.3: 2012-06-06
    Changes: Database references