Amino acid sequence of the effector domain of MRP. The amino acid residues K86-K109 are numbered starting from the N-terminal Gly residue of MRP, which becomes myristoylated. Basic amino acid residues are bold, and hydrophobic residues are underlined. P96, in the middle of the effector domain, is in italics. The two segments with mutated residues, SI (K89, K90, F91, S92 and F93) and SII (L99, S100, G101, L102 and F104), are shown in brackets.