Profile of the variation of amino acid sites, and occurrence of convergent and parallel substitutions. The PGRP specific segment absent in T7 lysozyme is indicated. Orange arrows correspond to parallel substitutions, and blue arrows indicate convergent substitutions. The secondary structure assignment is depicted above the profile. f is defined as the ratio of the number of different amino acids at a specified site to the total number of sequences compared.
Montaño et al. BMC Evolutionary Biology 2011 11:79 doi:10.1186/1471-2148-11-79