3G43

Crystal structure of the calmodulin-bound Cav1.2 C-terminal regulatory domain dimer


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Free: 0.269 
  • R-Value Work: 0.220 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Crystal structure of dimeric cardiac L-type calcium channel regulatory domains bridged by Ca2+{middle dot}calmodulins.

Fallon, J.L.Baker, M.R.Xiong, L.Loy, R.E.Yang, G.Dirksen, R.T.Hamilton, S.L.Quiocho, F.A.

(2009) Proc.Natl.Acad.Sci.USA 106: 5135-5140

  • DOI: 10.1073/pnas.0807487106

  • PubMed Abstract: 
  • Voltage-dependent calcium channels (Ca(V)) open in response to changes in membrane potential, but their activity is modulated by Ca(2+) binding to calmodulin (CaM). Structural studies of this family of channels have focused on CaM bound to the IQ mot ...

    Voltage-dependent calcium channels (Ca(V)) open in response to changes in membrane potential, but their activity is modulated by Ca(2+) binding to calmodulin (CaM). Structural studies of this family of channels have focused on CaM bound to the IQ motif; however, the minimal differences between structures cannot adequately describe CaM's role in the regulation of these channels. We report a unique crystal structure of a 77-residue fragment of the Ca(V)1.2 alpha(1) subunit carboxyl terminus, which includes a tandem of the pre-IQ and IQ domains, in complex with Ca(2+).CaM in 2 distinct binding modes. The structure of the Ca(V)1.2 fragment is an unusual dimer of 2 coiled-coiled pre-IQ regions bridged by 2 Ca(2+).CaMs interacting with the pre-IQ regions and a canonical Ca(V)1-IQ-Ca(2+).CaM complex. Native Ca(V)1.2 channels are shown to be a mixture of monomers/dimers and a point mutation in the pre-IQ region predicted to abolish the coiled-coil structure significantly reduces Ca(2+)-dependent inactivation of heterologously expressed Ca(V)1.2 channels.


    Related Citations: 
    • Structure of calmodulin bound to the hydrophobic IQ domain of the cardiac Ca(v)1.2 calcium channel.
      Fallon, J.L.,Halling, D.B.,Hamilton, S.L.,Quiocho, F.A.
      (2005) Structure 13: 1881


    Organizational Affiliation

    Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Calmodulin
A, B, C, D
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-dependent L-type calcium channel subunit alpha-1C
E, F
81Homo sapiensMutation(s): 0 
Gene Names: CACNA1C (CACH2, CACN2, CACNL1A1, CCHL1A1)
Find proteins for Q13936 (Homo sapiens)
Go to Gene View: CACNA1C
Go to UniProtKB:  Q13936
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CA
Query on CA

Download SDF File 
Download CCD File 
A, B, C, D
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Free: 0.269 
  • R-Value Work: 0.220 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 39.790α = 90.00
b = 113.980β = 90.00
c = 182.130γ = 90.00
Software Package:
Software NamePurpose
HKL-2000data scaling
HKL-3000data collection
PDB_EXTRACTdata extraction
DENZOdata reduction
CNSrefinement
SCALEPACKdata scaling
HKL-2000data reduction
CNSphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2009-03-03
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance
  • Version 1.2: 2017-11-01
    Type: Refinement description