2VAF

Crystal structure of Human Cardiac Calsequestrin


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.8 Å
  • R-Value Free: 0.325 
  • R-Value Work: 0.274 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Characterization of Human Cardiac Calsequestrin and its Deleterious Mutants.

Kim, E.Youn, B.Kemper, L.Campbell, C.Milting, H.Varsanyi, M.Kang, C.

(2007) J.Mol.Biol. 373: 1047

  • DOI: 10.1016/j.jmb.2007.08.055

  • PubMed Abstract: 
  • Mutations of conserved residues of human cardiac calsequestrin (hCSQ2), a high-capacity, low-affinity Ca2+-binding protein in the sarcoplasmic reticulum, have been associated with catecholamine-induced polymorphic ventricular tachycardia (CPVT). In o ...

    Mutations of conserved residues of human cardiac calsequestrin (hCSQ2), a high-capacity, low-affinity Ca2+-binding protein in the sarcoplasmic reticulum, have been associated with catecholamine-induced polymorphic ventricular tachycardia (CPVT). In order to understand the molecular mechanism and pathophysiological link between these CPVT-related missense mutations of hCSQ2 and the resulting arrhythmias, we generated three CPVT-causing mutants of hCSQ2 (R33Q, L167H, and D307H) and two non-pathological mutants (T66A and V76M) and investigated the effect of these mutations. In addition, we determined the crystal structure of the corresponding wild-type hCSQ2 to gain insight into the structural effects of those mutations. Our data show clearly that all three CPVT-related mutations lead to significant reduction in Ca2+-binding capacity in spite of the similarity of their secondary structures to that of the wild-type hCSQ2. Light-scattering experiments indicate that the Ca2+-dependent monomer-polymer transitions of the mutants are quite different, confirming that the linear polymerization behavior of CSQ is linked directly to its high-capacity Ca2+ binding. R33Q and D307H mutations result in a monomer that appears to be unable to form a properly oriented dimer. On the other hand, the L167H mutant has a disrupted hydrophobic core in domain II, resulting in high molecular aggregates, which cannot respond to Ca2+. Although one of the non-pathological mutants, T66A, shares characteristics with the wild-type, the other null mutant, V76M, shows significantly altered Ca2+-binding and polymerization behaviors, calling for careful reconsideration of its status.


    Organizational Affiliation

    School of Molecular Biosciences, Washington State University Pullman, WA 99164-4660, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
CALSEQUESTRIN-2
A
378Homo sapiensGene Names: CASQ2
Find proteins for O14958 (Homo sapiens)
Go to Gene View: CASQ2
Go to UniProtKB:  O14958
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.8 Å
  • R-Value Free: 0.325 
  • R-Value Work: 0.274 
  • Space Group: I 41 2 2
Unit Cell:
Length (Å)Angle (°)
a = 150.650α = 90.00
b = 150.650β = 90.00
c = 227.470γ = 90.00
Software Package:
Software NamePurpose
AMoREphasing
X-PLORrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2007-09-11
    Type: Initial release
  • Version 1.1: 2011-05-08
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance