4L1D

Voltage-gated sodium channel beta3 subunit Ig domain


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.5 Å
  • R-Value Free: 0.238 
  • R-Value Work: 0.202 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Crystal Structure and Molecular Imaging of the Nav Channel beta 3 Subunit Indicates a Trimeric Assembly.

Namadurai, S.Balasuriya, D.Rajappa, R.Wiemhofer, M.Stott, K.Klingauf, J.Edwardson, J.M.Chirgadze, D.Y.Jackson, A.P.

(2014) J.Biol.Chem. 289: 10797-10811

  • DOI: 10.1074/jbc.M113.527994

  • PubMed Abstract: 
  • The vertebrate sodium (Nav) channel is composed of an ion-conducting α subunit and associated β subunits. Here, we report the crystal structure of the human β3 subunit immunoglobulin (Ig) domain, a functionally important component of Nav channels in ...

    The vertebrate sodium (Nav) channel is composed of an ion-conducting α subunit and associated β subunits. Here, we report the crystal structure of the human β3 subunit immunoglobulin (Ig) domain, a functionally important component of Nav channels in neurons and cardiomyocytes. Surprisingly, we found that the β3 subunit Ig domain assembles as a trimer in the crystal asymmetric unit. Analytical ultracentrifugation confirmed the presence of Ig domain monomers, dimers, and trimers in free solution, and atomic force microscopy imaging also detected full-length β3 subunit monomers, dimers, and trimers. Mutation of a cysteine residue critical for maintaining the trimer interface destabilized both dimers and trimers. Using fluorescence photoactivated localization microscopy, we detected full-length β3 subunit trimers on the plasma membrane of transfected HEK293 cells. We further show that β3 subunits can bind to more than one site on the Nav 1.5 α subunit and induce the formation of α subunit oligomers, including trimers. Our results suggest a new and unexpected role for the β3 subunits in Nav channel cross-linking and provide new structural insights into some pathological Nav channel mutations.


    Organizational Affiliation

    From the Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, United Kingdom.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Sodium channel subunit beta-3
A, B, C
127Homo sapiensMutation(s): 0 
Gene Names: SCN3B (KIAA1158)
Find proteins for Q9NY72 (Homo sapiens)
Go to Gene View: SCN3B
Go to UniProtKB:  Q9NY72
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.5 Å
  • R-Value Free: 0.238 
  • R-Value Work: 0.202 
  • Space Group: P 31 2 1
Unit Cell:
Length (Å)Angle (°)
a = 81.469α = 90.00
b = 81.469β = 90.00
c = 114.257γ = 120.00
Software Package:
Software NamePurpose
XDSdata reduction
XSCALEdata scaling
PHENIXphasing
PHENIXmodel building
GDAdata collection
PHENIXrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2014-03-05
    Type: Initial release
  • Version 1.1: 2014-04-30
    Type: Database references