3G43

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


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.10 Å
  • R-Value Free: 0.269 
  • R-Value Work: 0.220 
  • R-Value Observed: 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 U S A 106: 5135-5140

  • DOI: 10.1073/pnas.0807487106
  • Structures With Same Primary Citation

  • 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: 
CALMCALM1CALM2CALM3CALML2CAMCAM1CAM2CAM3CAMB...
CALMCALM1CALM2CALM3CALML2CAMCAM1CAM2CAM3CAMBCAMCCAMIII

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
Voltage-dependent L-type calcium channel subunit alpha-1C
E, F
81Homo sapiensMutation(s): 0 
Gene Names: CACNA1CCACH2CACN2CACNL1A1CCHL1A1
Find proteins for Q13936 (Homo sapiens)
Go to UniProtKB:  Q13936
NIH Common Fund Data Resources
PHAROS  Q13936
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CA
Query on CA

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: 2.10 Å
  • R-Value Free: 0.269 
  • R-Value Work: 0.220 
  • R-Value Observed: 0.220 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 39.79α = 90
b = 113.98β = 90
c = 182.13γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
CNSphasing
CNSrefinement
PDB_EXTRACTdata extraction
HKL-3000data collection
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

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