Figure 5.

Phylogenetic analysis of PR-5d and the W34/W36/W196 aromatic surface motif. The tree of PR-5d and related proteins is a subtree from a larger neighbor-joining tree of PR-5 related proteins. Bootstrap values are indicated for two key clades. The residues in alignment positions 34, 36, and 196 (relative to the PR-5d sequence) have been mapped onto the tree, and demonstrate that the conserved putative binding site (W34/W36/W196) likely originated in an ancestral PR-5d protein in an ancestral species of the Solanaeceae family. The scale bar indicates units of number of amino acid substitutions per site.