Figure 4.—

Alignment of pheromone precursor sequences. The conserved ER/ED/ QR doublet considered to be at the N terminus of the mature pheromone is in boldface type as is a doublet of amino acids preceding the terminal cysteine residue. The C-terminal CaaX motif is underlined and the amino acids removed by C-terminal processing are shown in smaller type. Sequences obtained from O'Shea et al. (1998), Halsall et al. (2000), and Milner (2002) are indicated by (*). Pheromones are classified according to the pair of amino acids found at positions −1 and −2 with respect to the carboxy-terminal cysteine residue (the subterminal doublet); rr, both are aromatic; ar, an aliphatic and aromatic pair; aa, both are aliphatic.