6B8Q

Crystal Structure of the Mg2+/CaM:Kv7.5 (KCNQ5) AB domain complex


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.60 Å
  • R-Value Free: 0.270 
  • R-Value Work: 0.222 
  • R-Value Observed: 0.225 

Starting Model: experimental
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wwPDB Validation   3D Report Full Report


This is version 1.2 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: https://doi.org/10.1016/j.neuron.2018.01.035
  • Primary Citation of Related Structures:  
    6B8L, 6B8M, 6B8N, 6B8P, 6B8Q

  • 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 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:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Potassium voltage-gated channel subfamily KQT member 5
A, C, E, G
75Homo sapiensMutation(s): 0 
Gene Names: KCNQ5
UniProt & NIH Common Fund Data Resources
Find proteins for Q9NR82 (Homo sapiens)
Explore Q9NR82 
Go to UniProtKB:  Q9NR82
PHAROS:  Q9NR82
GTEx:  ENSG00000185760 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ9NR82
Sequence Annotations
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
Calmodulin-1
B, D, F, H
149Homo sapiensMutation(s): 0 
Gene Names: CALM1CALMCAMCAM1
UniProt & NIH Common Fund Data Resources
Find proteins for P0DP23 (Homo sapiens)
Explore P0DP23 
Go to UniProtKB:  P0DP23
PHAROS:  P0DP23
GTEx:  ENSG00000198668 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP0DP23
Sequence Annotations
Expand
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
MG
Query on MG

Download Ideal Coordinates CCD File 
I [auth B]
J [auth B]
K [auth B]
L [auth D]
M [auth D]
I [auth B],
J [auth B],
K [auth B],
L [auth D],
M [auth D],
N [auth D],
O [auth D],
P [auth F],
Q [auth F],
R [auth F],
S [auth F],
T [auth H],
U [auth H],
V [auth H],
W [auth H]
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.60 Å
  • R-Value Free: 0.270 
  • R-Value Work: 0.222 
  • R-Value Observed: 0.225 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 70.821α = 90
b = 116.845β = 90
c = 119.812γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
PDB_EXTRACTdata extraction
XDSdata reduction
XDSdata scaling
PHENIXphasing

Structure Validation

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Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute on Deafness and Other Communication Disorders (NIH/NIDCD)United StatesR01 DC007664

Revision History  (Full details and data files)

  • Version 1.0: 2018-03-14
    Type: Initial release
  • Version 1.1: 2019-12-18
    Changes: Author supporting evidence
  • Version 1.2: 2023-10-04
    Changes: Data collection, Database references, Derived calculations, Refinement description