4F8A

Cyclic nucleotide binding-homology domain from mouse EAG1 potassium channel


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.220 
  • R-Value Work: 0.189 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Structural, Biochemical, and Functional Characterization of the Cyclic Nucleotide Binding Homology Domain from the Mouse EAG1 Potassium Channel.

Marques-Carvalho, M.J.Sahoo, N.Muskett, F.W.Vieira-Pires, R.S.Gabant, G.Cadene, M.Schonherr, R.Morais-Cabral, J.H.

(2012) J.Mol.Biol. 423: 34-46

  • DOI: 10.1016/j.jmb.2012.06.025

  • PubMed Abstract: 
  • KCNH channels are voltage-gated potassium channels with important physiological functions. In these channels, a C-terminal cytoplasmic region, known as the cyclic nucleotide binding homology (CNB-homology) domain displays strong sequence similarity t ...

    KCNH channels are voltage-gated potassium channels with important physiological functions. In these channels, a C-terminal cytoplasmic region, known as the cyclic nucleotide binding homology (CNB-homology) domain displays strong sequence similarity to cyclic nucleotide binding (CNB) domains. However, the isolated domain does not bind cyclic nucleotides. Here, we report the X-ray structure of the CNB-homology domain from the mouse EAG1 channel. Through comparison with the recently determined structure of the CNB-homology domain from the zebrafish ELK (eag-like K(+)) channel and the CNB domains from the MlotiK1 and HCN (hyperpolarization-activated cyclic nucleotide-gated) potassium channels, we establish the structural features of CNB-homology domains that explain the low affinity for cyclic nucleotides. Our structure establishes that the "self-liganded" conformation, where two residues of the C-terminus of the domain are bound in an equivalent position to cyclic nucleotides in CNB domains, is a conserved feature of CNB-homology domains. Importantly, we provide biochemical evidence that suggests that there is also an unliganded conformation where the C-terminus of the domain peels away from its bound position. A functional characterization of this unliganded conformation reveals a role of the CNB-homology domain in channel gating.


    Related Citations: 
    • Crystallization and preliminary X-ray crystallographic characterization of a cyclic nucleotide-binding homology domain from the mouse EAG potassium channel.
      Marques-Carvalho, M.J.,Morais-Cabral, J.H.
      (2012) Acta Crystallogr.,Sect.F 68: 337


    Organizational Affiliation

    Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua do Campo Alegre 823, 4150-180 Porto, Portugal.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Potassium voltage-gated channel subfamily H member 1
A
160Mus musculusMutation(s): 0 
Gene Names: Kcnh1 (Eag)
Find proteins for Q60603 (Mus musculus)
Go to UniProtKB:  Q60603
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.220 
  • R-Value Work: 0.189 
  • Space Group: P 31 2 1
Unit Cell:
Length (Å)Angle (°)
a = 60.346α = 90.00
b = 60.346β = 90.00
c = 85.415γ = 120.00
Software Package:
Software NamePurpose
PHENIXrefinement
ADSCdata collection
PDB_EXTRACTdata extraction
MOSFLMdata reduction
SCALAdata scaling
PHASERphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2012-07-11
    Type: Initial release
  • Version 1.1: 2012-10-17
    Type: Database references