3WFN

Crystal Structure of Nav1.6 IQ motif in complex with apo-CaM


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free: 0.237 
  • R-Value Work: 0.200 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Structural Basis for the Modulation of the Neuronal Voltage-Gated Sodium Channel NaV1.6 by Calmodulin

Chichili, V.P.R.Xiao, Y.Seetharaman, J.Cummins, T.R.Sivaraman, J.

(2013) Sci Rep 3: 2435-2435

  • DOI: 10.1038/srep02435

  • PubMed Abstract: 
  • The neuronal-voltage gated sodium channel (VGSC), Na(V)1.6, plays an important role in propagating action potentials along myelinated axons. Calmodulin (CaM) is known to modulate the inactivation kinetics of Na(V)1.6 by interacting with its IQ motif. ...

    The neuronal-voltage gated sodium channel (VGSC), Na(V)1.6, plays an important role in propagating action potentials along myelinated axons. Calmodulin (CaM) is known to modulate the inactivation kinetics of Na(V)1.6 by interacting with its IQ motif. Here we report the crystal structure of apo-CaM:Na(V)1.6IQ motif, along with functional studies. The IQ motif of Na(V)1.6 adopts an α-helical conformation in its interaction with the C-lobe of CaM. CaM uses different residues to interact with Na(V)1.6IQ motif depending on the presence or absence of Ca²⁺. Three residues from Na(V)1.6, Arg1902, Tyr1904 and Arg1905 were identified as the key common interacting residues in both the presence and absence of Ca²⁺. Substitution of Arg1902 and Tyr1904 with alanine showed a reduced rate of Na(V)1.6 inactivation in electrophysiological experiments in vivo. Compared with other CaM:Na(V) complexes, our results reveal a different mode of interaction for CaM:Na(V)1.6 and provides structural insight into the isoform-specific modulation of VGSCs.


    Organizational Affiliation

    Department of Biological Sciences, National University of Singapore, Singapore, 117543.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Calmodulin, Sodium channel protein type 8 subunit alpha
B, C, D, E
182Mus musculusMutation(s): 0 
Gene Names: Scn8a (Nbna1), Calm2 (Cam2, CamC)
Find proteins for Q9WTU3 (Mus musculus)
Go to UniProtKB:  Q9WTU3
Find proteins for P0DP27 (Mus musculus)
Go to UniProtKB:  P0DP27
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free: 0.237 
  • R-Value Work: 0.200 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 72.830α = 90.00
b = 50.752β = 91.48
c = 150.666γ = 90.00
Software Package:
Software NamePurpose
HKL-2000data scaling
PHENIXmodel building
PHENIXrefinement
PHENIXphasing
ADSCdata collection
HKL-2000data reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2013-08-28
    Type: Initial release
  • Version 1.1: 2017-08-16
    Type: Source and taxonomy