Table 2. Amino-acid preferences in the binding grooves of BIR2 and BIR3.

Data adapted from Franklin et al. (2003 ▶) and Sweeney et al. (2006 ▶).

	P1	P2	P3	P4
BIR2	Ala >> Ser	Smaller aromatic or Pro	Ala > Arg/Lys/Val	Val/Ala/Ile/Gly
BIR3	Ala >> Val	Lys/Arg > branched aliphatic	Pro >> Arg Ala	Phe/Tyr > Ile/Leu