Figure 3.

Amino acid sequence alignment of the serine protease domains deduced from the Xenopus ovochymase proenzyme cDNA (ovotryptase1 and 2 and ovochymase) with Xenopus oviductal protease oviductin (GenBank accession no. U81291), Xenopus trypsin (P19799), human elastase 2a (P08217), and bovine chymotrypsin (P00767). Sequence alignment was performed with clustal-w (27). Conserved (consensus) amino acids are capitalized and in bold when at least four of seven amino acids are identical. Serine active-site amino acids are marked with diamonds, and the S1 substrate binding site is indicated by an arrowhead. The position of cleavage for protease activation is marked with an arrow.