Human survivin (NP_001159) is aligned using ClustalW to both BIR domains of A. fumigatus BIR1 (XP_752777). Disruption of either Phe86 or Val89 (red frames) in survivin inhibits S12 binding; asterisks mark residues forming the interface between survivin dimers (10). Amino acid abbreviations: A, Ala; C, Cys; D, Asp; E, Glu; F, Phe; G, Gly; H, His; I, Ile; K, Lys; L, Leu; M, Met; N, Asn; P, Pro; Q, Gln; R, Arg; S, Ser; T, Thr; V, Val; W, Trp; Y, Tyr.