1NW9

STRUCTURE OF CASPASE-9 IN AN INHIBITORY COMPLEX WITH XIAP-BIR3

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.40 Å
  • R-Value Free: 0.235 
  • R-Value Work: 0.230 
  • R-Value Observed: 0.230 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history. 


Literature

Mechanism of XIAP-Mediated Inhibition of Caspase-9

Shiozaki, E.N., Chai, J., Rigotti, D.J., Riedl, S.J., Li, P., Srinivasula, S.M., Alnemri, E.S., Fairman, R., Shi, Y.

(2003) Mol Cell 11: 519-527

  • DOI: 10.1016/s1097-2765(03)00054-6
  • Primary Citation of Related Structures:  
    1NW9

  • PubMed Abstract: 

    • The inhibitor of apoptosis (IAP) proteins potently inhibit the catalytic activity of caspases. While profound insight into the inhibition of the effector caspases has been gained in recent years, the mechanism of how the initiator caspase-9 is regulated ...

    The inhibitor of apoptosis (IAP) proteins potently inhibit the catalytic activity of caspases. While profound insight into the inhibition of the effector caspases has been gained in recent years, the mechanism of how the initiator caspase-9 is regulated by IAPs remains enigmatic. This paper reports the crystal structure of caspase-9 in an inhibitory complex with the third baculoviral IAP repeat (BIR3) of XIAP at 2.4 A resolution. The structure reveals that the BIR3 domain forms a heterodimer with a caspase-9 monomer. Strikingly, the surface of caspase-9 that interacts with BIR3 also mediates its homodimerization. We demonstrate that monomeric caspase-9 is catalytically inactive due to the absence of a supporting sequence element that could be provided by homodimerization. Thus, XIAP sequesters caspase-9 in a monomeric state, which serves to prevent catalytic activity. These studies, in conjunction with other observations, define a unified mechanism for the activation of all caspases.

    Organizational Affiliation: 

    Department of Molecular Biology, Lewis Thomas Laboratory, Princeton University, Princeton, NJ 08544, USA.



Macromolecules
Find similar proteins by: 
(by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Baculoviral IAP repeat-containing protein 4 A98Homo sapiensMutation(s): 0 
Gene Names: BIRC4 OR API3 OR IAP3 OR XIAP, XIAP, API3, BIRC4, IAP3
EC: 2.3.2.27
Find proteins for P98170 (Homo sapiens)
Explore P98170 
Go to UniProtKB:  P98170
NIH Common Fund Data Resources
PHAROS:  P98170
GTEx:  ENSG00000101966
Protein Feature View
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  • Reference Sequence
Find similar proteins by: 
(by identity cutoff)  |  Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
caspase 9, apoptosis-related cysteine protease B277Homo sapiensMutation(s): 0 
Gene Names: CASP9, MCH6
EC: 3.4.22.62
Find proteins for P55211 (Homo sapiens)
Explore P55211 
Go to UniProtKB:  P55211
NIH Common Fund Data Resources
PHAROS:  P55211
GTEx:  ENSG00000132906
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ZN
Query on ZN
Download Ideal Coordinates CCD File 
A
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N		 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.40 Å
  • R-Value Free: 0.235 
  • R-Value Work: 0.230 
  • R-Value Observed: 0.230 
  • Space Group: P 65 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 104.4α = 90
b = 104.4β = 90
c = 170.3γ = 120
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
AMoREphasing
CNSrefinement

Structure Validation

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View more in-depth experimental data

Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2003-03-25
    Type: Initial release
  • Version 1.1: 2008-04-29
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2018-10-03
    Changes: Advisory, Data collection