In silico prediction of the glycosomal enzymes of Leishmania major and trypanosomes

In total, 37 080 protein sequences of the three trypanosomatids Leishmania major, Trypanosoma brucei and Trypanosoma cruzi, were used to predict the trypanosomatid glycosomal proteome. All protein sequences were analyzed for the presence of either a C-terminal (PTS1) or an N-terminal (PTS2) peroxisomal targeting sequence. For L. major 191 potential PTS1-containing proteins and 68 potential PTS2-containing proteins with homologues in T. brucei and T. cruzi were identified. About 50% of them were hypothetical proteins to which no function was attributed. From those proteins with known function it appears that the predicted glycosomal proteome of L. major strongly resembles that of T. brucei and T. cruzi with respect to enzyme content. Glycosomes are not only involved in glycolysis, but are predicted to carry out also gluconeogenesis, reactions of the hexose-monophosphate pathway, purine salvage and pyrimidine biosynthesis, β-oxidation of fatty acids, fatty acid elongation and the biosynthesis of ether lipids. In addition, they seem to catalyze several reactions of isoprenoid synthesis and are involved in oxidant stress protection.