1NW9

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


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.4 Å
  • R-Value Free: 0.235 
  • R-Value Work: 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

  • Also Cited By: 1TW6

  • 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 regula ...

    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: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Baculoviral IAP repeat-containing protein 4
A
98Homo sapiensMutation(s): 0 
Gene Names: XIAP (API3, BIRC4, IAP3)
EC: 2.3.2.27
Find proteins for P98170 (Homo sapiens)
Go to Gene View: XIAP
Go to UniProtKB:  P98170
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
caspase 9, apoptosis-related cysteine protease
B
277Homo sapiensMutation(s): 0 
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
ZN
Query on ZN

Download SDF File 
Download CCD File 
A
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.4 Å
  • R-Value Free: 0.235 
  • R-Value Work: 0.230 
  • Space Group: P 65 2 2
Unit Cell:
Length (Å)Angle (°)
a = 104.400α = 90.00
b = 104.400β = 90.00
c = 170.300γ = 120.00
Software Package:
Software NamePurpose
AMoREphasing
SCALEPACKdata scaling
DENZOdata reduction
CNSrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

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