Most photosynthetic eukaryotes synthesize both heme and chlorophyll via a common tetrapyrrole biosynthetic pathway starting from glutamate. This pathway was derived mainly from cyanobacterial predecessor of the plastid and differs from the heme synthesis of the plastid-lacking eukaryotes. Here, we show that the coral-associated alveolate Chromera velia, the closest known photosynthetic relative to Apicomplexa, possesses a tetrapyrrole pathway that is homologous to the unusual pathway of apicomplexan parasites. We also demonstrate that, unlike other eukaryotic phototrophs, Chromera synthesizes chlorophyll from glycine and succinyl-CoA rather than glutamate. Our data shed light on the evolution of the heme biosynthesis in parasitic Apicomplexa and photosynthesis-related biochemical processes in their ancestors.
Kořený, L., Sobotka, R., Janouškovec, J., Keeling, P. J., & Oborník, M. (2011). Tetrapyrrole Synthesis of Photosynthetic Chromerids Is Likely Homologous to the Unusual Pathway of Apicomplexan Parasites
. The Plant Cell, 23(9), 3454–3462. doi:10.1105/tpc.111.089102
This work was supported by the Czech Science Foundation (GA206/08/1423), the Grant Agency of the Academy of Sciences of the Czech Republic (IAA601410907), by Award IC/2010/09 made by King Abdullah University of Science and Technology, by the project Algatech (CZ.1.05/2.1.00/03.0110), and by the Grant Agency of University of South Bohemia (GAJU 146/2010/P) to M.O.; by Institutional Research Concept AV0Z50200510 to R.S.; and by the Canadian Institutes for Health Research (MOP42517) to P.J.K. P.J.K. is a Fellow of the Canadian Institute for Advanced Research and a Senior Scholar of the Michael Smith Foundation for Health Research.