Major metabolic pathways in the anaerobic intestinal parasite Entamoeba histolytica, a parasitic amoeboid protist and the causative agent of amoebiasis. Major metabolic pathways in the anaerobic intestinal parasite Entamoeba histolytica, a parasitic amoeboid protist and the causative agent of amoebiasis. The map is redrawn based on data reported previously (354). The amoebozoan infects humans and other primates; its energy metabolic pathways are localized in the cytosol, which also harbors mitosomes (5, 507). Pyruvate:ferredoxin oxidoreductase is used for pyruvate decarboxylation/oxidation, as in parabasalian parasites; ATP is synthesized through substrate-level phosphorylation via acetyl-CoA synthetase (ADP forming) (431). Although not involved in energy metabolism, mitosomes in E. histolytica harbor enzymes of sulfate activation as a major function (332). Abbreviations: Fd, ferredoxin; [1], pyruvate:ferredoxin oxidoreductase; [5], malic enzyme; [9], pyruvate kinase; [11], malate dehydrogenase; [18], alanine aminotransferase; [25], alcohol dehydrogenase E; [28], phosphoenolpyruvate carboxytransferase (PPi dependent); [29], pyruvate:orthophosphate dikinase; [30], acetyl-CoA synthetase (ADP forming). The photograph shows an Entamoeba histolytica trophozoite with an ingested erythrocyte, with a length of ca. 20 μm. (Photograph from the Centers for Disease Control and Prevention [CDC], Atlanta, GA.)‏ Miklós Müller et al. Microbiol. Mol. Biol. Rev. 2012; doi:10.1128/MMBR.05024-11