Figure 3. The T. cruzi sterol biosynthesis pathway.

The figure shows the metabolic steps leading from farnesyl-diphosphate to ergosterol (in yeast, and in T. cruzi epimastigotes) or to different 24-alkylsterols (in T. cruzi amastigotes [64]), and the corresponding yeast and T. cruzi enzymes that catalyze these steps. The two methyl groups at C4 are removed in two rounds of successive C4-oxidation, C4-decarboxylation and C3-ketoreduction (*). Gene names used are those in Tables 1 and 2. Unknown/hypothetical assignments are shown with question marks.