6MUD

Voltage-gated sodium channel NaV1.5 C-terminal domain in complex with Ca2+/Calmodulin


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.69 Å
  • R-Value Free: 0.269 
  • R-Value Work: 0.212 
  • R-Value Observed: 0.215 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Crystal structures of Ca2+-calmodulin bound to NaVC-terminal regions suggest role for EF-hand domain in binding and inactivation.

Gardill, B.R.Rivera-Acevedo, R.E.Tung, C.C.Van Petegem, F.

(2019) Proc Natl Acad Sci U S A 116: 10763-10772

  • DOI: 10.1073/pnas.1818618116
  • Structures With Same Primary Citation

  • PubMed Abstract: 
  • Voltage-gated sodium (Na V ) and calcium channels (Ca V ) form targets for calmodulin (CaM), which affects channel inactivation properties. A major interaction site for CaM resides in the C-terminal (CT) region, consisting of an ...

    Voltage-gated sodium (Na V ) and calcium channels (Ca V ) form targets for calmodulin (CaM), which affects channel inactivation properties. A major interaction site for CaM resides in the C-terminal (CT) region, consisting of an IQ domain downstream of an EF-hand domain. We present a crystal structure of fully Ca 2+ -occupied CaM, bound to the CT of Na V 1.5. The structure shows that the C-terminal lobe binds to a site ∼90° rotated relative to a previous site reported for an apoCaM complex with the Na V 1.5 CT and for ternary complexes containing fibroblast growth factor homologous factors (FHF). We show that the binding of FHFs forces the EF-hand domain in a conformation that does not allow binding of the Ca 2+ -occupied C-lobe of CaM. These observations highlight the central role of the EF-hand domain in modulating the binding mode of CaM. The binding sites for Ca 2+ -free and Ca 2+ -occupied CaM contain targets for mutations linked to long-QT syndrome, a type of inherited arrhythmia. The related Na V 1.4 channel has been shown to undergo Ca 2+ -dependent inactivation (CDI) akin to Ca V s. We present a crystal structure of Ca 2+ /CaM bound to the Na V 1.4 IQ domain, which shows a binding mode that would clash with the EF-hand domain. We postulate the relative reorientation of the EF-hand domain and the IQ domain as a possible conformational switch that underlies CDI.


    Organizational Affiliation

    Department of Biochemistry and Molecular Biology, Life Sciences Institute, The University of British Columbia, Vancouver, BC, Canada V6T 1Z3 filip.vanpetegem@gmail.com.



Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Calmodulin-1
A
149Homo sapiensMutation(s): 0 
Gene Names: CALM1CALMCAMCAM1
Find proteins for P0DP23 (Homo sapiens)
Go to UniProtKB:  P0DP23
NIH Common Fund Data Resources
PHAROS  P0DP23

Find similar proteins by: Sequence  |  Structure

Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Sodium channel protein type 5 subunit alpha
B
140Homo sapiensMutation(s): 0 
Gene Names: SCN5A
Find proteins for Q14524 (Homo sapiens)
Go to UniProtKB:  Q14524
NIH Common Fund Data Resources
PHAROS  Q14524
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CA
Query on CA

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

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.69 Å
  • R-Value Free: 0.269 
  • R-Value Work: 0.212 
  • R-Value Observed: 0.215 
  • Space Group: I 2 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 65.579α = 90
b = 84.032β = 90
c = 140.684γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
PDB_EXTRACTdata extraction
XDSdata reduction
XDSdata scaling
PHASERphasing

Structure Validation

View Full Validation Report



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Canadian Institutes of Health Research (CIHR)CanadaMOP-119404

Revision History 

  • Version 1.0: 2019-05-08
    Type: Initial release
  • Version 1.1: 2019-05-22
    Changes: Data collection, Database references
  • Version 1.2: 2019-06-12
    Changes: Data collection, Database references
  • Version 1.3: 2020-01-08
    Changes: Author supporting evidence