5HIT

Crystal Structure Analysis of Ca2+-calmodulin and a C-terminal EAG1 channel fragment


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.85 Å
  • R-Value Free: 0.268 
  • R-Value Work: 0.205 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Molecular Insights into the Mechanism of Calmodulin Inhibition of the EAG1 Potassium Channel.

Marques-Carvalho, M.J.Oppermann, J.Munoz, E.Fernandes, A.S.Gabant, G.Cadene, M.Heinemann, S.H.Schonherr, R.Morais-Cabral, J.H.

(2016) Structure 24: 1742-1754

  • DOI: 10.1016/j.str.2016.07.020

  • PubMed Abstract: 
  • The human EAG1 potassium channel belongs to the superfamily of KCNH voltage-gated potassium channels that have roles in cardiac repolarization and neuronal excitability. EAG1 is strongly inhibited by Ca <sup>2+ </sup>/calmodulin (CaM) through a mecha ...

    The human EAG1 potassium channel belongs to the superfamily of KCNH voltage-gated potassium channels that have roles in cardiac repolarization and neuronal excitability. EAG1 is strongly inhibited by Ca 2+ /calmodulin (CaM) through a mechanism that is not understood. We determined the binding properties of CaM with each one of three previously identified binding sites (BDN, BDC1, and BDC2), analyzed binding to protein stretches that include more than one site, and determined the effect of neighboring globular domains on the binding properties. The determination of the crystal structure of CaM bound to BDC2 shows the channel fragment interacting with only the C lobe of calmodulin and adopting an unusual bent conformation. Based on this structure and on a functional and biochemical analysis of mutants, we propose a model for the mechanism of inhibition whereby the local conformational change induced by CaM binding at BDC2 lies at the basis of channel modulation.


    Organizational Affiliation

    Instituto de Biologia Molecular e Celular, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal; Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal. Electronic address: jcabral@ibmc.up.pt.,Instituto de Biologia Molecular e Celular, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal; Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal.,Department of Biophysics, Center for Molecular Biomedicine, Friedrich Schiller University Jena and Jena University Hospital, 07745 Jena, Germany.,Software 4 Science Developments, 15782 Santiago de Compostela, Spain.,Centre de Biophysique Moléculaire, CNRS UPR430, 45071 Orléans, France.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Calmodulin
A
147Gallus gallusMutation(s): 0 
Gene Names: CALM (CAM)
Find proteins for P62149 (Gallus gallus)
Go to UniProtKB:  P62149
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Potassium voltage-gated channel subfamily H member 1
B
17Mus musculusMutation(s): 0 
Gene Names: Kcnh1 (Eag)
Find proteins for Q60603 (Mus musculus)
Go to UniProtKB:  Q60603
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CA
Query on CA

Download SDF File 
Download CCD File 
A
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.85 Å
  • R-Value Free: 0.268 
  • R-Value Work: 0.205 
  • Space Group: C 2 2 21
Unit Cell:
Length (Å)Angle (°)
a = 53.624α = 90.00
b = 121.137β = 90.00
c = 73.855γ = 90.00
Software Package:
Software NamePurpose
Aimlessdata scaling
PHENIXrefinement
PDB_EXTRACTdata extraction
PHASERphasing
XDSdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2016-09-14
    Type: Initial release
  • Version 1.1: 2016-09-21
    Type: Database references
  • Version 1.2: 2016-09-28
    Type: Database references
  • Version 1.3: 2016-10-19
    Type: Database references