Figure 1.

Cystatin-like extracellular protease inhibitors in Phytophthora spp. A, Sequence alignment of P. infestans EPIC1 to EPIC4 proteins with chicken egg white cystatin (CHKCYS, P01038), a type member of cystatin-like Cys protease inhibitors. The proposed active sites of cystatins, including the N-terminal trunk (NT), first binding loop (L1), and second binding loop (L2), are shown. Amino acid residues that define cystatins are marked with asterisks. The predicted signal peptides are shown in italics. B, Phylogenetic relationships of 13 cystatin-like extracellular proteinase inhibitors from P. infestans, P. sojae, and P. ramorum. The neighbor-joining tree was generated as described in “Materials and Methods” using the sequences listed in Table I. The tree was rooted with chicken egg white cystatin (CHKCYS, P01038). Bootstrap values were obtained with 1,000 replications, and values higher than 50% are shown. The length of the branches reflects weighted amino acid substitutions, and the scale bar indicates 10% weighted sequence divergence. The two clusters of orthologous genes identified in the three species are indicated by vertical lines.