2L53

Solution NMR Structure of apo-calmodulin in complex with the IQ motif of Human Cardiac Sodium Channel NaV1.5


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 200 
  • Conformers Submitted: 20 
  • Selection Criteria: structures with the lowest energy 

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This is version 1.1 of the entry. See complete history

Literature

Solution NMR Structure of Apo-Calmodulin in Complex with the IQ Motif of Human Cardiac Sodium Channel NaV1.5.

Chagot, B.Chazin, W.J.

(2011) J.Mol.Biol. 406: 106-119

  • DOI: 10.1016/j.jmb.2010.11.046

  • PubMed Abstract: 
  • The function of the human voltage-gated sodium channel Na(V)1.5 is regulated in part by intracellular calcium signals. The ubiquitous calcium sensor protein calmodulin (CaM) is an important part of the complex calcium-sensing apparatus in Na(V)1.5. C ...

    The function of the human voltage-gated sodium channel Na(V)1.5 is regulated in part by intracellular calcium signals. The ubiquitous calcium sensor protein calmodulin (CaM) is an important part of the complex calcium-sensing apparatus in Na(V)1.5. CaM interacts with an IQ (isoleucine-glutamine) motif in the large intracellular C-terminal domain of the channel. Using co-expression and co-purification, we have been able to isolate a CaM-IQ motif complex and to determine its high-resolution structure in absence of calcium using multi-dimensional solution NMR. Under these conditions, the Na(V)1.5 IQ motif interacts with the C-terminal domain (C-lobe) of CaM, with the N-terminal domain remaining free in solution. The structure reveals that the C-lobe adopts a semi-open conformation with the IQ motif bound in a narrow hydrophobic groove. Sequence similarities between voltage-gated sodium channels and voltage-gated calcium channels suggest that the structure of the CaM-Na(V)1.5 IQ motif complex can serve as a general model for the interaction between CaM and ion channel IQ motifs under low-calcium conditions. The structure also provides insight into the biochemical basis for disease-associated mutations that map to the IQ motif in Na(V)1.5.


    Organizational Affiliation

    Department of Biochemistry, Vanderbilt University, Nashville, TN 37232, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Calmodulin
A
148Homo sapiensMutation(s): 0 
Gene Names: CALM2 (CAM2, CAMB)
Find proteins for P0DP24 (Homo sapiens)
Go to Gene View: CALM2
Go to UniProtKB:  P0DP24
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Voltage-gated sodium channel type V alpha isoform b variant
B
31Homo sapiensMutation(s): 0 
Gene Names: SCN5A
Find proteins for Q14524 (Homo sapiens)
Go to Gene View: SCN5A
Go to UniProtKB:  Q14524
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 200 
  • Conformers Submitted: 20 
  • Selection Criteria: structures with the lowest energy 
  • Olderado: 2L53 Olderado

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2011-01-05
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance