The mitochondrial ATP synthase of Trypanosoma brucei: structure and regulation.

The structure and regulation of the Trypanosoma brucei mitochondrial ATP synthase is reviewed. This enzyme complex which catalyzes the synthesis and hydrolysis of ATP within the mitochondrion is a multisubunit complex which is regulated in several ways. Several lines of evidence have shown that the ATP synthase is regulated through the life cycle of Trypanosoma brucei. The enzyme complex is present at maximal levels in the procyclic form where mitochondrial activity is the highest and cytochromes and Kreb's cycle components are present. The levels of the ATP synthase are decreased in the bloodstream forms where the levels of the mitochondrial cytochromes are absent or substantially decreased. In recent preliminary work we have shown the presence of an ATP synthase inhibitor peptide which may indicate an additional level of complexity to the regulation.