2AR9

Crystal structure of a dimeric caspase-9


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.8 Å
  • R-Value Free: 0.288 
  • R-Value Work: 0.237 

wwPDB Validation 3D Report Full Report


This is version 1.4 of the entry. See complete history

Literature

Engineering a Dimeric Caspase-9: A Re-Evaluation of the Induced Proximity Model for Caspase Activation

Chao, Y.Shiozaki, E.N.Srinivassula, S.M.Rigotti, D.J.Fairman, R.Shi, Y.

(2005) PLOS BIOL. 3: 1079-1087

  • DOI: 10.1371/journal.pbio.0030183

  • PubMed Abstract: 
  • Caspases are responsible for the execution of programmed cell death (apoptosis) and must undergo proteolytic activation, in response to apoptotic stimuli, to function. The mechanism of initiator caspase activation has been generalized by the induced ...

    Caspases are responsible for the execution of programmed cell death (apoptosis) and must undergo proteolytic activation, in response to apoptotic stimuli, to function. The mechanism of initiator caspase activation has been generalized by the induced proximity model, which is thought to drive dimerization-mediated activation of caspases. The initiator caspase, caspase-9, exists predominantly as a monomer in solution. To examine the induced proximity model, we engineered a constitutively dimeric caspase-9 by relieving steric hindrance at the dimer interface. Crystal structure of the engineered caspase-9 closely resembles that of the wild-type (WT) caspase-9, including all relevant structural details and the asymmetric nature of two monomers. Compared to the WT caspase-9, this engineered dimer exhibits a higher level of catalytic activity in vitro and induces more efficient cell death when expressed. However, the catalytic activity of the dimeric caspase-9 is only a small fraction of that for the Apaf-1-activated caspase-9. Furthermore, in contrast to the WT caspase-9, the activity of the dimeric caspase-9 can no longer be significantly enhanced in an Apaf-1-dependent manner. These findings suggest that dimerization of caspase-9 may be qualitatively different from its activation by Apaf-1, and in conjunction with other evidence, posit an induced conformation model for the activation of initiator caspases.


    Organizational Affiliation

    Department of Molecular Biology, Lewis Thomas Laboratory, Princeton University, Princeton, New Jersey, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Caspase-9
A, B, C, D
278Homo sapiensMutation(s): 6 
Gene Names: CASP9 (MCH6)
EC: 3.4.22.62
Find proteins for P55211 (Homo sapiens)
Go to Gene View: CASP9
Go to UniProtKB:  P55211
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
MLT
Query on MLT

Download SDF File 
Download CCD File 
A
D-MALATE
(2R)-2-HYDROXYBUTANEDIOIC ACID; 2-HYDROXY-SUCCINIC ACID
C4 H6 O5
BJEPYKJPYRNKOW-UWTATZPHSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.8 Å
  • R-Value Free: 0.288 
  • R-Value Work: 0.237 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 144.698α = 90.00
b = 78.055β = 112.50
c = 125.963γ = 90.00
Software Package:
Software NamePurpose
DENZOdata reduction
AMoREphasing
SCALEPACKdata scaling
CNSrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2005-10-11
    Type: Initial release
  • Version 1.1: 2008-04-30
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2011-11-16
    Type: Atomic model
  • Version 1.4: 2012-02-15
    Type: Non-polymer description