Crystal Structure of Caspase-activated DNase (CAD)

Experimental Data Snapshot

  • Resolution: 2.60 Å
  • R-Value Free: 0.246 
  • R-Value Work: 0.218 
  • R-Value Observed: 0.218 

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Structural Mechanism for Inactivation and Activation of Cad/Dff40 in the Apoptotic Pathway

Woo, E.-J.Kim, Y.-G.Kim, M.-S.Han, W.-D.Shin, S.Robinson, H.Park, S.-Y.Oh, B.-H.

(2004) Mol Cell 14: 531

  • DOI: https://doi.org/10.1016/s1097-2765(04)00258-8
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    CAD/DFF40 is responsible for the degradation of chromosomal DNA into nucleosomal fragments and subsequent chromatin condensation during apoptosis. It exists as an inactive complex with its inhibitor ICAD/DFF45 in proliferating cells but becomes activated upon cleavage of ICAD/DFF45 into three domains by caspases in dying cells. The molecular mechanism underlying the control and activation of CAD/DFF40 was unknown. Here, the crystal structure of activated CAD/DFF40 reveals that it is a pair of molecular scissors with a deep active-site crevice that appears ideal for distinguishing internucleosomal DNA from nucleosomal DNA. Ensuing studies show that ICAD/DFF45 sequesters the nonfunctional CAD/DFF40 monomer and is also able to disassemble the functional CAD/DFF40 dimer. This capacity requires the involvement of the middle domain of ICAD/DFF45, which by itself cannot remain bound to CAD/DFF40 due to low binding affinity for the enzyme. Thus, the consequence of the caspase-cleavage of ICAD/DFF45 is a self-assembly of CAD/DFF40 into the active dimer.

  • Organizational Affiliation

    Division of Molecular and Life Sciences, Department of Life Sciences and Center for Biomolecular Recognition, Pohang University of Science and Technology, Pohang, Kyungbuk 790-784, South Korea.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
DNA FRAGMENTATION FACTOR 40 KDA SUBUNIT329Mus musculusMutation(s): 0 
Gene Names: DffbCad
EC: 3
UniProt & NIH Common Fund Data Resources
Find proteins for O54788 (Mus musculus)
Explore O54788 
Go to UniProtKB:  O54788
IMPC:  MGI:1196287
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupO54788
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.60 Å
  • R-Value Free: 0.246 
  • R-Value Work: 0.218 
  • R-Value Observed: 0.218 
  • Space Group: P 64
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 110.189α = 90
b = 110.189β = 90
c = 73.982γ = 120
Software Package:
Software NamePurpose
SCALEPACKdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2004-05-21
    Type: Initial release
  • Version 1.1: 2011-05-07
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance