title: Tetrapyrrole synthesis of photosynthetic chromerids is likely homologous to the unusual pathway of apicomplexan parasites.
abstract: 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.
authors.affiliation: Institute of Parasitology, Biology Centre, Academy of Sciences of the Czech Republic, and Faculty of Science, University of South Bohemia, Czech Republic.
authors.forename: Ludek
authors.initials: L
authors.lastname: Koreny
authors.forename: Roman
authors.initials: R
authors.lastname: Sobotka
authors.forename: Jan
authors.initials: J
authors.lastname: Janouskovec
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Keeling
authors.forename: Miroslav
authors.initials: M
authors.lastname: Oborník
mesh_terms: D000214:Acyl Coenzyme A / Q000378:metabolism; D056893:Alveolata / Q000378:metabolism*; D002734:Chlorophyll / Q000096:biosynthesis*; D016054:DNA, Protozoan / Q000235:genetics; D005998:Glycine / Q000378:metabolism; D008969:Molecular Sequence Data; D010788:Photosynthesis; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D045725:Tetrapyrroles / Q000096:biosynthesis*
chemical_list: D000214:Acyl Coenzyme A; D016054:DNA, Protozoan; D045725:Tetrapyrroles; D002734:Chlorophyll; C012046:succinyl-coenzyme A; D005998:Glycine