Source: ImmunoDB
http://cegg.unige.ch/insecta/immunodb/

IAPs: Inhibitors of Apoptosis
Summary

Sang Woon Shin(1), Guowu Bian(1), Kanwal Alvarez(1), Alexander Raikhel(1), and Bart Bryant(2) 

1. Department of Entomology and the Institute for Integrative Genome Biology, University of California, Riverside California 92521, USA 2. Division of Biology, Kansas State University, Rollie Clem Lab, Ackert Hall, Manhattan, KS 66506-4901 

IAPs are characterized by a 70-residue domain, the baculoviral IAP repeat (BIR). In Dm, four IAPs were found with distinct domain architecture. DmIAP2 encodes a protein that has three N-terminal BIR (baculovirus IAP repeat) domains and a C-terminal RING-finger (Really Interesting New Gene) domain. Although the previously characterized IAPs were shown to be inhibitors of caspases [Deveraux & Reed 1999], it is unlikely that DmIAP2 directly inhibits DREDD. The depletion of DmIAP2 leads to disruption of the Imd pathway and did not result in an enhancement or constitutive expression of immune genes [Gesellchen et al. 2005; Kleino et al. 2005]. In both Ag and Aa genomes, clear 1:1 orthologs of three Dm IAPs (DmIAP1, DmBRUCE and CG12265) were found. Whereas AgIAP2, the closest homolog of DmIAP2, was predicted to contain only one BIR domain, AaIAP2 contains three BIR domains and a C-terminal RING-finger, showing clear 1:1 ortholog relationship to DmIAP2. The phylogenetic tree is derived from the alignment of the BIR domains of IAPs from all three species, with domains labeled a, b, or c from the N to the C terminal of the respective proteins. The only BIR of AgIAP2 is shown as AgIAP2_domain c because it clusters with the c domain of DmIAP2 and AaIAP2. Domain a of AgIAP7 is not included in the tree as it is incomplete, although the partial sequence does cluster with AgIAP3/4_domain a. AgIAP8 and AaIAP9 have one BIR domain each, they are excluded from the tree as they disrupt the alignment, although AgIAP8 may cluster with domain c of IAP2. 

Orme & Meier, 2009, Apoptosis PMID:19495985 
Inhibitor of apoptosis proteins in Drosophila: gatekeepers of death.