3OX5

Crystal Structure of the calcium sensor calcium-binding protein 1 (CaBP1)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.9 Å
  • R-Value Free: 0.250 
  • R-Value Work: 0.213 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Structural Basis for the Differential Effects of CaBP1 and Calmodulin on Ca(V)1.2 Calcium-Dependent Inactivation.

Findeisen, F.Minor, D.L.

(2010) Structure 18: 1617-1631

  • DOI: 10.1016/j.str.2010.09.012
  • Primary Citation of Related Structures:  3OX6

  • PubMed Abstract: 
  • Calcium-binding protein 1 (CaBP1), a calmodulin (CaM) homolog, endows certain voltage-gated calcium channels (Ca(V)s) with unusual properties. CaBP1 inhibits Ca(V)1.2 calcium-dependent inactivation (CDI) and introduces calcium-dependent facilitation ...

    Calcium-binding protein 1 (CaBP1), a calmodulin (CaM) homolog, endows certain voltage-gated calcium channels (Ca(V)s) with unusual properties. CaBP1 inhibits Ca(V)1.2 calcium-dependent inactivation (CDI) and introduces calcium-dependent facilitation (CDF). Here, we show that the ability of CaBP1 to inhibit Ca(V)1.2 CDI and induce CDF arises from interaction between the CaBP1 N-lobe and interlobe linker residue Glu94. Unlike CaM, where functional EF hands are essential for channel modulation, CDI inhibition does not require functional CaBP1 EF hands. Furthermore, CaBP1-mediated CDF has different molecular requirements than CaM-mediated CDF. Overall, the data show that CaBP1 comprises two structural modules having separate functions: similar to CaM, the CaBP1 C-lobe serves as a high-affinity anchor that binds the Ca(V)1.2 IQ domain at a site that overlaps with the Ca²+/CaM C-lobe site, whereas the N-lobe/linker module houses the elements required for channel modulation. Discovery of this division provides the framework for understanding how CaBP1 regulates Ca(V)s.


    Organizational Affiliation

    Cardiovascular Research Institute, University of California, San Francisco, CA 94158-2330, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Calcium-binding protein 1
A, B, C, D, E, F
153Homo sapiensGene Names: CABP1
Find proteins for Q9NZU7 (Homo sapiens)
Go to Gene View: CABP1
Go to UniProtKB:  Q9NZU7
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, E, F
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.9 Å
  • R-Value Free: 0.250 
  • R-Value Work: 0.213 
  • Space Group: I 2 3
Unit Cell:
Length (Å)Angle (°)
a = 206.044α = 90.00
b = 206.044β = 90.00
c = 206.044γ = 90.00
Software Package:
Software NamePurpose
PHENIXmodel building
MOSFLMdata reduction
REFMACrefinement
PHENIXphasing
SCALAdata scaling
HKL-2000data collection

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2010-12-22
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance