BIR Domain

**Semantic type:** Amino Acid Sequence

**Definition:** Containing perfectly conserved histidine and cysteines residues. the BIR domain is about 70 residues long arranged in tandem repeats separated by a linker of variable length. Found in IAP (Inhibitor of Apoptosis Protein) Family proteins, it seems to confer cell death-preventing activity. Except NAIP, family members typically contain two or three BIR repeats and a C-terminal RING finger. A second group of BIR-domain-containing proteins (BIRPs) include mammalian Bruce and Survivin proteins, as well as BIR-containing proteins in yeasts and C. elegans. Survivin-like BIRPs regulate cytokinesis and mitotic spindle formation. (NCI)

**Synonyms:** - BIR Motif - Baculovirus Inhibitor of Apoptosis Protein Repeat - IAP Repeat - Inhibitor of Apoptosis Domain