Evolutionary Origin of Anaerobic Mitochondria

It is now generally accepted that the classical aerobic mitochondria evolved by a single endosymbiotic event between an anaerobic host and an a-proteobacterium. Endosymbiotic theories for the origin of cellular 

Anaerobic metabolism is usually considered to be an old and rather primitive way of life, but the scenario described here would imply that anaerobically functioning mitochondria are an adaptation of the traditional type of mitochondria to anaerobic environments hence, these anaerobic mitochondria are in fact a further evolution of aerobic mitochondria. 

Ackrell BAC, Johnson MK, Gunsalus RP, Cecchini G (1992) Structure and function of succinate dehydrogenase and fumarate reductase. In Muller F (ed) Chemistry and biochemistry of flavoenzymes, vol III. CRC, Boca Raton, pp 229-297 Allen PC (1973) Helminths comparison of their rhodoquinone. Exp Parasitol 34 211-219 

Bruchhaus I, Tannich E (1994) Purification and molecular characterization of the NAD(+)-dependent acetaldehyde/alcohol dehydrogenase from Entamoeba histolytica. Biochem J 303(Pt 3) 743-748 

Burger G, Gray MW, Lang BF (2003) Mitochondrial genomes anything goes. Trends Genet 19 709-716 

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