3UKV

Structure of the C-linker/CNBHD of zELK channels in P 1 21 1 space group, crystallized in the presence of cAMP


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.7 Å
  • R-Value Free: 0.277 
  • R-Value Work: 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:  

  • 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 ...

    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: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Novel protein similar to vertebrate potassium voltage-gated channel, subfamily H (Eag-related) family
B, A, C, D
212Danio rerioMutation(s): 0 
Gene Names: kcnh3
Find proteins for A8WHX9 (Danio rerio)
Go to UniProtKB:  A8WHX9
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.7 Å
  • R-Value Free: 0.277 
  • R-Value Work: 0.215 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 55.330α = 90.00
b = 106.420β = 97.51
c = 77.520γ = 90.00
Software Package:
Software NamePurpose
PHASERphasing
HKL-2000data collection
BOSdata collection
MOSFLMdata reduction
SCALAdata scaling
PHENIXrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

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

Revision History 

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