Ubiquinone metabolism

Ubiquinone, also known as coenzyme Q is an integral component of electron transport chain. In electron transport chain of inner mitochondrial membrane, ubiquinone acts as an electron carrier transferring electrons from NADH dehydrogenase (complex I) and succinate dehydrogenase (complex II) to cytochrome bc1 complex (complex III). Ubiquinone is synthesised from chorimsate, end product of shikimate pathway in nine enzyme-catalysed reactions. The other important co-substrates involved in this pathway are glutamine, isoprenoids (terpenoid metabolism) and S-adenosyl methionine (methionine metabolism). This pathway is identical in all apicomplexans including Toxoplasma gondii, Neospora caninum and Plasmodium falciparum and the enzymes missing in the genomes of all these species are oxo-acid lyase and 3-octaprenyl-4-hydroxybenzoate carboxy-lyase.

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Sources and fates of metabolites