Inhibitor of apoptosis domain

The inhibitor of apoptosis domain -- also known as IAP repeat, Baculovirus Inhibitor of apoptosis protein Repeat, or BIR -- is a structural motif found in proteins with roles in apoptosis, cytokine production, and chromosome segregation.^[2] Proteins containing BIR are known as inhibitor of apoptosis proteins (IAPs), or BIR-containing proteins (BIRPs or BIRCs), and include BIRC1 (NAIP), BIRC2 (cIAP1), BIRC3 (cIAP2), BIRC4 (xIAP), BIRC5 (survivin) and BIRC6.^[2][3]

Inhibitor of Apoptosis domain
NMR solution structure of the BIR domain of human BIRC2 protein.[1] The protein is rainbow colored cartoon diagram (N-terminus = blue, C-terminus = red) while the coordinated zinc is represented by a grey sphere.
Identifiers
Symbol	BIR
Pfam	PF00653
InterPro	IPR001370
PROSITE	PS50143
SCOP2	1qbh / SCOPe / SUPFAM
Available protein structures: Pfam   structures / ECOD   PDB RCSB PDB; PDBe; PDBj PDBsum structure summary PDB 1c9q​, 1e31​, 1f3h​, 1f9x​, 1g3f​, 1g73​, 1i3o​, 1jd4​, 1jd5​, 1jd6​, 1m4m​, 1nw9​, 1oxn​, 1oxq​, 1oy7​, 1q4q​, 1qbh​, 1sdz​, 1se0​, 1tfq​, 1tft​, 1tw6​, 1xb0​, 1xb1​, 1xox​, 2i3h​, 2i3i​

BIR domains belong to the zinc-finger domain family and characteristically have a number of invariant amino acid residues, including 3 conserved cysteines and one conserved histidine, which coordinate a zinc ion.^[4] They are typically composed of 4-5 alpha helices and a three-stranded beta sheet.

External links

• Eukaryotic Linear Motif resource motif class LIG_BIR_II_1
• Eukaryotic Linear Motif resource motif class LIG_BIR_III_1
• Eukaryotic Linear Motif resource motif class LIG_BIR_III_2
• Eukaryotic Linear Motif resource motif class LIG_BIR_III_3
• Eukaryotic Linear Motif resource motif class LIG_BIR_III_4