Evolution of the haem synthetic pathway in kinetoplastid flagellates: An essential pathway that is not essential after all?

0342950 - BC 2011 RIV AU eng J - Journal Article
Kořený, Luděk - Lukeš, Julius - Oborník, Miroslav
Evolution of the haem synthetic pathway in kinetoplastid flagellates: An essential pathway that is not essential after all?
International Journal for Parasitology. Roč. 40, č. 2 (2010), s. 149-156. ISSN 0020-7519. E-ISSN 1879-0135
R&D Projects: GA ČR GA206/08/1423; GA ČR GD206/09/H026
Institutional research plan: CEZ:AV0Z60220518
Keywords : haem synthesis * Kinetoplastida * evolution * horizontal gene transfer * bacterial endosymbiont
Subject RIV: EB - Genetics ; Molecular Biology
Impact factor: 3.822, year: 2010

Kinetoplastid flagellates represent an interesting group of species, as some of them lost the complete pathway of haem synthesis while others possess only the last 3 biosynthetic steps. We decided to supplement a Current view on the phylogeny of these important pathogens with the expected state of haem synthesis in representative species. We propose a scenario in which the ancestor of all trypanosomatids was completely deficient of the synthesis of haem. In trypanosomatids other than members of the genus Trypanosoma, the pathway was partially rescued by genes encoding enzymes for the last three steps, Supposedly obtained by horizontal transfer from a gamma-proteobacterium. This event preceded the diversification of the non-Trypanosoma trypanosomatids. Later, some flagellates acquired a beta-proteobacterial endosymbiont which supplied them with haem precursors. The medically important trypanosomes have remained fully deficient of haem synthesis and obtain this compound from the host.
Permanent Link: http://hdl.handle.net/11104/0185550