2VSL

Crystal Structure of XIAP BIR3 with a Bivalent Smac Mimetic


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Free: 0.226 
  • R-Value Work: 0.218 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Interaction of a Cyclic, Bivalent Smac Mimetic with the X-Linked Inhibitor of Apoptosis Protein.

Nikolovska-Coleska, Z.Meagher, J.L.Jiang, S.Yang, C.Y.Qiu, S.Roller, P.P.Stuckey, J.A.Wang, S.

(2008) Biochemistry 47: 9811

  • DOI: 10.1021/bi800785y

  • PubMed Abstract: 
  • We have designed and synthesized a cyclic, bivalent Smac mimetic (compound 3) and characterized its interaction with the X-linked inhibitor of apoptosis protein (XIAP). Compound 3 binds to XIAP containing both BIR2 and BIR3 domains with a biphasic do ...

    We have designed and synthesized a cyclic, bivalent Smac mimetic (compound 3) and characterized its interaction with the X-linked inhibitor of apoptosis protein (XIAP). Compound 3 binds to XIAP containing both BIR2 and BIR3 domains with a biphasic dose-response curve representing two binding sites with IC 50 values of 0.5 and 406 nM, respectively. Compound 3 binds to XIAPs containing the BIR3-only and BIR2-only domain with K i values of 4 nM and 4.4 microM, respectively. Gel filtration experiments using wild-type and mutated XIAPs showed that 3 forms a 1:2 stoichiometric complex with XIAP containing the BIR3-only domain. However, it forms a 1:1 stoichiometric complex with XIAP containing both BIR2 and BIR3 domains, and both BIR domains are involved in the binding. Compound 3 efficiently antagonizes inhibition of XIAP in a cell-free functional assay and is >200 times more potent than its corresponding monovalent compound 2. Determination of the crystal structure of 3 in complex with the XIAP BIR3 domain confirms that 3 induces homodimerization of the XIAP BIR3 domain and provides a structural basis for the cooperative binding of one molecule of compound 3 to two XIAP BIR3 molecules. On the basis of this crystal structure, a binding model of XIAP containing both BIR2 and BIR3 domains and 3 was constructed, which sheds light on the ability of 3 to relieve the inhibition of XIAP with not only caspase-9 but also caspase-3/-7. Compound 3 is cell-permeable, effectively activates caspases in whole cells, and potently inhibits cancer cell growth. Compound 3 is a useful biochemical and pharmacological tool for further elucidating the role of XIAP in regulation of apoptosis and represents a promising lead compound for the design of potent, cell-permeable Smac mimetics for cancer treatment.


    Organizational Affiliation

    Department of Internal Medicine, Comprehensive Cancer Center, University of Michigan, 1500 East Medical Center Drive, Ann Arbor, Michigan 48109, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
BACULOVIRAL IAP REPEAT-CONTAINING PROTEIN 4
A
96Homo 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
PEPTIDE (MAA-LYS-PRO-PHE)
B
4N/AMutation(s): 0 
Protein Feature View is not available: No corresponding UniProt sequence found.
Small Molecules
Ligands 2 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
15P
Query on 15P

Download SDF File 
Download CCD File 
A
POLYETHYLENE GLYCOL (N=34)
PEG 1500
C69 H140 O35
VUYXVWGKCKTUMF-UHFFFAOYSA-N
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
MAA
Query on MAA
B
L-peptide linkingC4 H9 N O2ALA
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Free: 0.226 
  • R-Value Work: 0.218 
  • Space Group: I 4 2 2
Unit Cell:
Length (Å)Angle (°)
a = 102.478α = 90.00
b = 102.478β = 90.00
c = 65.218γ = 90.00
Software Package:
Software NamePurpose
MOLREPphasing
SCALEPACKdata scaling
CNSrefinement
DENZOdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2008-09-02
    Type: Initial release
  • Version 1.1: 2016-12-28
    Type: Derived calculations, Non-polymer description, Other, Source and taxonomy, Version format compliance