The apicoplast and mitochondrion of Toxoplasma gondii

Toxoplasma gondii possesses two organelles derived by endosymbiosis, the mitochondrion, and a plastid-derived compartment called the apicoplast. Both organelles house are important metabolic pathways and are essential for the parasite. The mitochondrion has many canonical features, including pathways for ATP production and for the synthesis of key cofactors, although it also has key differences from mitochondria of host species. The apicoplast is a legacy of a secondary endosymbiotic acquisition of a red alga. Although no longer photosynthetic, the apicoplast houses numerous biochemical pathways that are absent from host species, making it a promising drug target. In this chapter, we describe the evolutionary history and molecular and cell biology of both organelles and outline the essential roles several metabolic pathways have for the survival of the parasite.