6B8P

Crystal Structure of the Mg2+/CaM:Kv7.4 (KCNQ4) AB domain complex

  • Classification: METAL TRANSPORT
  • Organism(s): Homo sapiens
  • Expression System: Escherichia coli

  • Deposited: 2017-10-09 Released: 2018-03-14 
  • Deposition Author(s): Chang, A., Minor, D.L.
  • Funding Organization(s): National Institutes of Health/Eunice Kennedy Shriver National Institute of Child Health & Human Development 

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.240 
  • R-Value Work: 0.207 

wwPDB Validation 3D Report Full Report


This is version 1.0 of the entry. See complete history

Literature

A Calmodulin C-Lobe Ca

Chang, A.Abderemane-Ali, F.Hura, G.L.Rossen, N.D.Gate, R.E.Minor, D.L.

(2018) Neuron 97: 836-852.e6

  • DOI: 10.1016/j.neuron.2018.01.035
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Kv7 (KCNQ) voltage-gated potassium channels control excitability in the brain, heart, and ear. Calmodulin (CaM) is crucial for Kv7 function, but how this calcium sensor affects activity has remained unclear. Here, we present X-ray crystallographic an ...

    Kv7 (KCNQ) voltage-gated potassium channels control excitability in the brain, heart, and ear. Calmodulin (CaM) is crucial for Kv7 function, but how this calcium sensor affects activity has remained unclear. Here, we present X-ray crystallographic analysis of CaM:Kv7.4 and CaM:Kv7.5 AB domain complexes that reveal an Apo/CaM clamp conformation and calcium binding preferences. These structures, combined with small-angle X-ray scattering, biochemical, and functional studies, establish a regulatory mechanism for Kv7 CaM modulation based on a common architecture in which a CaM C-lobe calcium-dependent switch releases a shared Apo/CaM clamp conformation. This C-lobe switch inhibits voltage-dependent activation of Kv7.4 and Kv7.5 but facilitates Kv7.1, demonstrating that mechanism is shared by Kv7 isoforms despite the different directions of CaM modulation. Our findings provide a unified framework for understanding how CaM controls different Kv7 isoforms and highlight the role of membrane proximal domains for controlling voltage-gated channel function. VIDEO ABSTRACT.


    Organizational Affiliation

    Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA 94158, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Potassium voltage-gated channel subfamily KQT member 4
A, C, E, G
82Homo sapiensMutation(s): 0 
Gene Names: KCNQ4
Find proteins for P56696 (Homo sapiens)
Go to Gene View: KCNQ4
Go to UniProtKB:  P56696
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Calmodulin-1
B, D, F, H
149Homo sapiensMutation(s): 0 
Gene Names: CALM1 (CALM, CAM, CAM1)
Find proteins for P0DP23 (Homo sapiens)
Go to Gene View: CALM1
Go to UniProtKB:  P0DP23
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

Download SDF File 
Download CCD File 
C, E, F, H
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
MG
Query on MG

Download SDF File 
Download CCD File 
B, D, F, H
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.240 
  • R-Value Work: 0.207 
  • Space Group: I 2 2 2
Unit Cell:
Length (Å)Angle (°)
a = 108.141α = 90.00
b = 142.875β = 90.00
c = 164.082γ = 90.00
Software Package:
Software NamePurpose
PHENIXrefinement
PHENIXphasing
PDB_EXTRACTdata extraction
XSCALEdata scaling
XDSdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History & Funding Information

Deposition Data

  • Deposited Date: 2017-10-09 
  • Released Date: 2018-03-14 
  • Deposition Author(s): Chang, A., Minor, D.L.

Funding OrganizationLocationGrant Number
National Institutes of Health/Eunice Kennedy Shriver National Institute of Child Health & Human DevelopmentUnited StatesR01 DC007664

Revision History 

  • Version 1.0: 2018-03-14
    Type: Initial release