title: Divergent mitochondrial respiratory chains in phototrophic relatives of apicomplexan parasites.
abstract: Four respiratory complexes and ATP-synthase represent central functional units in mitochondria. In some mitochondria and derived anaerobic organelles, a few or all of these respiratory complexes have been lost during evolution. We show that the respiratory chain of Chromera velia, a phototrophic relative of parasitic apicomplexans, lacks complexes I and III, making it a uniquely reduced aerobic mitochondrion. In Chromera, putative lactate:cytochrome c oxidoreductases are predicted to transfer electrons from lactate to cytochrome c, rendering complex III unnecessary. The mitochondrial genome of Chromera has the smallest known protein-coding capacity of all mitochondria, encoding just cox1 and cox3 on heterogeneous linear molecules. In contrast, another photosynthetic relative of apicomplexans, Vitrella brassicaformis, retains the same set of genes as apicomplexans and dinoflagellates (cox1, cox3, and cob).
authors: Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic Life Science Research Centre, Department of Biology and Ecology, Faculty of Science, University of Ostrava, Ostrava, Czech Republic obornik@paru.cas.cz jula@paru.cas.cz.
authors: Pavel
authors: P
authors: Flegontov
authors: Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic obornik@paru.cas.cz jula@paru.cas.cz.
authors: Jan
authors: J
authors: Michálek
authors: Department of Botany, University of BC, Vancouver, Canada Canadian Institute for Advanced Research, Toronto, ON, Canada obornik@paru.cas.cz jula@paru.cas.cz.
authors: Jan
authors: J
authors: Janouškovec
authors: Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic obornik@paru.cas.cz jula@paru.cas.cz.
authors: De-Hua
authors: DH
authors: Lai
authors: Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic.
authors: Milan
authors: M
authors: Jirků
authors: Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic.
authors: Eva
authors: E
authors: Hajdušková
authors: Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic.
authors: Aleš
authors: A
authors: Tomčala
authors: Wellcome Trust Sanger Institute, Hinxton, United Kingdom.
authors: Thomas D
authors: TD
authors: Otto
authors: Department of Botany, University of BC, Vancouver, Canada Canadian Institute for Advanced Research, Toronto, ON, Canada.
authors: Patrick J
authors: PJ
authors: Keeling
authors: Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Kingdom of Saudi Arabia.
authors: Arnab
authors: A
authors: Pain
authors: Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic Institute of Microbiology, Czech Academy of Sciences, Třeboň, Czech Republic obornik@paru.cas.cz jula@paru.cas.cz.
authors: Miroslav
authors: M
authors: Oborník
authors: Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic Canadian Institute for Advanced Research, Toronto, ON, Canada obornik@paru.cas.cz jula@paru.cas.cz.
authors: Julius
authors: J
authors: Lukeš
mesh_terms: D056893:Alveolata / Q000235:genetics / Q000378:metabolism; D000818:Animals; D016782:Apicomplexa / Q000235:genetics; D045304:Cytochromes c / Q000378:metabolism; D004579:Electron Transport; D042967:Electron Transport Complex I / Q000235:genetics / Q000378:metabolism; D019143:Evolution, Molecular; D014644:Genetic Variation; D054629:Genome, Mitochondrial; D019344:Lactic Acid / Q000378:metabolism; D008928:Mitochondria / Q000235:genetics* / Q000378:metabolism; D025261:Mitochondrial Proton-Translocating ATPases / Q000235:genetics / Q000378:metabolism; D010271:Parasites / Q000235:genetics / Q000378:metabolism; D010788:Photosynthesis / Q000235:genetics; D010802:Phylogeny
chemical_list: D019344:Lactic Acid; D045304:Cytochromes c; D025261:Mitochondrial Proton-Translocating ATPases; D042967:Electron Transport Complex I
keywords: Apicomplexa; Chromera; Vitrella; anaerobic metabolism; evolution; respiratory chain