Alignment of the predicted amino acid sequences of the PSA-1 transcripts (panel A) and PSA-2 transcripts (panel B).

The signal peptide is indicated in red italics. The residues that make up the catalytic triad are in blue and are indicated by arrows. The activation sequence is in bold and underlined. The unique 16-residue sequence that emanates from use of intron 3 is shown in green bold italic. The alignments were carried out using the CLUTALW program available at http://www.ebi.ac.uk/toolsmsa/clustalw2/ (Thompson et al., 1994 [41]).