title: Prokaryotic ancestry and gene fusion of a dual localized peroxiredoxin in malaria parasites.
abstract: Horizontal gene transfer has emerged as a crucial driving force for the evolution of eukaryotes. This also includesPlasmodium falciparumand related economically and clinically relevant apicomplexan parasites, whose rather small genomes have been shaped not only by natural selection in different host populations but also by horizontal gene transfer following endosymbiosis. However, there is rather little reliable data on horizontal gene transfer between animal hosts or bacteria and apicomplexan parasites. Here we show that apicomplexan homologues of peroxiredoxin 5 (Prx5) have a prokaryotic ancestry and therefore represent a special subclass of Prx5 isoforms in eukaryotes. Using two different immunobiochemical approaches, we found that theP. falciparumPrx5 homologue is dually localized to the parasite plastid and cytosol. This dual localization is reflected by a modularPlasmodium-specific gene architecture consisting of two exons. Despite the plastid localization, our phylogenetic analyses contradict an acquisition by secondary endosymbiosis and support a gene fusion event following a horizontal prokaryote-to-eukaryote gene transfer in early apicomplexans. The results provide unexpected insights into the evolution of apicomplexan parasites as well as the molecular evolution of peroxiredoxins, an important family of ubiquitous, usually highly concentrated thiol-dependent hydroperoxidases that exert functions as detoxifying enzymes, redox sensors and chaperones.
authors.affiliation: Department of Parasitology, Ruprecht-Karls University, D-69120 Heidelberg, Germany.
authors.forename: Carine F
authors.initials: CF
authors.lastname: Djuika
authors.affiliation: Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), D-69117 Heidelberg, Germany.
authors.forename: Jaime
authors.initials: J
authors.lastname: Huerta-Cepas
authors.affiliation: Department of Parasitology, Philipps University, D-35043 Marburg, Germany.
authors.forename: Jude M
authors.initials: JM
authors.lastname: Przyborski
authors.affiliation: Department of Parasitology, Ruprecht-Karls University, D-69120 Heidelberg, Germany.
authors.forename: Sophia
authors.initials: S
authors.lastname: Deil
authors.affiliation: Department of Parasitology, Ruprecht-Karls University, D-69120 Heidelberg, Germany.
authors.forename: Cecilia P
authors.initials: CP
authors.lastname: Sanchez
authors.affiliation: Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), D-69117 Heidelberg, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Doerks
authors.affiliation: Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), D-69117 Heidelberg, Germany.
authors.forename: Peer
authors.initials: P
authors.lastname: Bork
authors.affiliation: Department of Parasitology, Ruprecht-Karls University, D-69120 Heidelberg, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Lanzer
authors.affiliation: Department of Parasitology, Ruprecht-Karls University, D-69120 Heidelberg, Germany.
authors.forename: Marcel
authors.initials: M
authors.lastname: Deponte
keywords: apicomplexa; horizontal gene transfer; malaria; molecular evolution; peroxiredoxin