sentences:  Survivin is 16.5 kDa large and is the smallest member of the IAP family.X-ray crystallography has shown two molecules of human surviving coming together to form a bowtie-shape dimer through a hydrophobic interface.This interface includes N-terminal residues 6-10 just before the BIR domain region and the 10 residue region connecting the BIR domain to the C-terminal helix.