1i3o

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spinqualitylabelsall models 1i3o, resolution 2.7Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

CRYSTAL STRUCTURE OF THE COMPLEX OF XIAP-BIR2 AND CASPASE 3

Contents 1 Overview 2 Disease 3 About this Structure 4 Reference

Overview

The molecular mechanism(s) that regulate apoptosis by caspase inhibition remain poorly understood. The main endogenous inhibitors are members of the IAP family and are exemplified by XIAP, which regulates the initiator caspase-9, and the executioner caspases-3 and -7. We report the crystal structure of the second BIR domain of XIAP (BIR2) in complex with caspase-3, at a resolution of 2.7 A, revealing the structural basis for inhibition. The inhibitor makes limited contacts through its BIR domain to the surface of the enzyme, and most contacts to caspase-3 originate from the N-terminal extension. This lies across the substrate binding cleft, but in reverse orientation compared to substrate binding. The mechanism of inhibition is due to a steric blockade prohibitive of substrate binding, and is distinct from the mechanism utilized by synthetic substrate analog inhibitors.

Disease

Known diseases associated with this structure: Lymphoproliferative syndrome, X-linked, 2 OMIM:[300079]

About this Structure

1I3O is a Protein complex structure of sequences from Homo sapiens with as ligand. Full crystallographic information is available from OCA.

Reference

Structural basis for the inhibition of caspase-3 by XIAP., Riedl SJ, Renatus M, Schwarzenbacher R, Zhou Q, Sun C, Fesik SW, Liddington RC, Salvesen GS, Cell. 2001 Mar 9;104(5):791-800. PMID:11257232

Page seeded by OCA on Thu Feb 21 13:07:42 2008