Alignment of amino acid sequences of trypsins. The completely conserved sites (19) are marked by black boxes. The catalytic triad (His, Asp, Ser) is denoted by stars above the sequences. Amino acid sequences are shown for: TPC, trypsin from P. camtschatica (Q8WR10); TPV, trypsin from Pen. vannamei (Q27761); TAF, trypsin from Astacus fluviatilis (P00765); TSA, trypsin from Squalus acanthias (P00764); TBT, trypsin from Bos taurus (Q29463); TAA, trypsin from Aedes aegypti (P29787); TDM, trypsin from Drosophila melanogaster (P04814); and TSG, trypsin from S. griseus (P00775). Swiss-Prot database accession numbers are given in parentheses. The numbers above the sequences follow the established chymotrypsinogen numbering system.