Background: Mitochondrial acetate production is essential for viability of the procyclic trypanosomes and probably many other protists. Results:We identified an acetyl-CoA thioesterase (ACH) contributing to acetate production from acetyl-CoA. Conclusion: Acetate production by ASCT, but not by ACH, is involved in ATP production. Significance: In trypanosomes and probably other protists, ASCT/SCoAS cycle-derived ATP production can substitute for oxidative phosphorylation.

Background:The role of pyruvate phosphate dikinase (PPDK), which catalyzes a reversible reaction, is unknown in many eukaryotes. Results: Deletion of the trypanosomal PPDK gene affects glycolysis. Conclusion:In trypanosomes, PPDK works in the glycolytic direction and participates in the maintenance of the glycosomal ATP/ADP balance. Significance: The glycosomal PPDK provides a metabolic flexibility by producing 2 ATP per phosphoenolpyruvate consumed.