1se0
From Proteopedia
Crystal structure of DIAP1 BIR1 bound to a Grim peptide
Structural highlights
Function[IAP1_DROME] Anti-apoptotic protein which functions as a caspase regulator, using its E3 ubiquitin-protein ligase activity to smother caspase activity. Binds, ubiquitinates and inactivates initiator caspase Nc, and effector caspases ICE and DCP-1. Acts as a NEDD8-E3 ubiquitin-protein ligase for ICE. Suppresses apoptosis by targeting the apoptosome for ubiquitination and inactivation. Plays an important role in cell motility. Overexpression suppresses rpr and W-dependent cell death in the eye. Interaction of th with Nc is required to suppress Nc-mediated cell death; th-mediated ubiquitination of Nc. Acts as a positive regulator of Wnt signaling.[1] [2] [3] [4] [5] [6] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe Drosophila melanogaster inhibitor of apoptosis protein DIAP1 suppresses apoptosis in part through inhibition of the effector caspase DrICE. The pro-death proteins Reaper, Hid and Grim (RHG) induce apoptosis by antagonizing DIAP1 function. However, the underlying molecular mechanisms remain unknown. Here we demonstrate that DIAP1 directly inhibits the catalytic activity of DrICE through its BIR1 domain and this inhibition is countered effectively by the RHG proteins. Inhibition of DrICE by DIAP1 occurs only after the cleavage of its N-terminal 20 amino acids and involves a conserved surface groove on BIR1. Crystal structures of BIR1 bound to the RHG peptides show that the RHG proteins use their N-terminal IAP-binding motifs to bind to the same surface groove, hence relieving DIAP1-mediated inhibition of DrICE. These studies define novel molecular mechanisms for the inhibition and activation of a representative D. melanogaster effector caspase. Molecular mechanisms of DrICE inhibition by DIAP1 and removal of inhibition by Reaper, Hid and Grim.,Yan N, Wu JW, Chai J, Li W, Shi Y Nat Struct Mol Biol. 2004 May;11(5):420-8. Epub 2004 Apr 25. PMID:15107838[7] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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