An evolutionary analysis of trypanosomatid GP63 proteases.

The trypanosomatid GP63 proteases are known to be involved in parasite-host interaction and exhibit strong sequence and structural similarities to those of their hosts and insect vectors. Based on genome sequences of the three trypanosomatids, Trypanosoma brucei, Trypanosoma cruzi, and Leishmania spp., we annotated all their GP63 proteases and divided highly duplicated T. cruzi GP63 proteases into four novel groups according to sequence features. In Leishmania spp., we studied the evolutionary dynamics of GP63 proteins and identified 57 amino acid sites that are under significant positive selections. These sites may contribute to the functional variations of the GP63 proteases and provide clues for vaccine development.