title: Frataxin, a conserved mitochondrial protein, in the hydrogenosome of Trichomonas vaginalis.
abstract: Recent data suggest that frataxin plays a key role in eukaryote cellular iron metabolism, particularly in mitochondrial heme and iron-sulfur (FeS) cluster biosynthesis. We have now identified a frataxin homologue (T. vaginalis frataxin) from the human parasite Trichomonas vaginalis. Instead of mitochondria, this unicellular eukaryote possesses hydrogenosomes, peculiar organelles that produce hydrogen but nevertheless share common ancestry with mitochondria. T. vaginalis frataxin contains conserved residues implicated in iron binding, and in silico, it is predicted to form a typical alpha-beta sandwich motif. The short N-terminal extension of T. vaginalis frataxin resembles presequences that target proteins to hydrogenosomes, a prediction confirmed by the results of overexpression of T. vaginalis frataxin in T. vaginalis. When expressed in the mitochondria of a frataxin-deficient Saccharomyces cerevisiae strain, T. vaginalis frataxin partially restored defects in heme and FeS cluster biosynthesis. Although components of heme synthesis or heme-containing proteins have not been found in T. vaginalis to date, T. vaginalis frataxin was also shown to interact with S. cerevisiae ferrochelatase by using a Biacore assay. The discovery of conserved iron-metabolizing pathways in mitochondria and hydrogenosomes provides additional evidence not only of their common evolutionary history, but also of the fundamental importance of this pathway for eukaryotes.
authors.affiliation: Department of Parasitology, Charles University, Faculty of Science, Vinicna 7, 128 44 Prague, Czech Republic.
authors.forename: Pavel
authors.initials: P
authors.lastname: Dolezal
authors.forename: Andrew
authors.initials: A
authors.lastname: Dancis
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Lesuisse
authors.forename: Róbert
authors.initials: R
authors.lastname: Sutak
authors.forename: Ivan
authors.initials: I
authors.lastname: Hrdý
authors.forename: T Martin
authors.initials: TM
authors.lastname: Embley
authors.forename: Jan
authors.initials: J
authors.lastname: Tachezy
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017124:Conserved Sequence; D033862:Iron-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D024101:Mitochondrial Proteins / Q000235:genetics* / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D015388:Organelles / Q000378:metabolism*; D016415:Sequence Alignment; D014158:Transcription, Genetic; D014246:Trichomonas vaginalis / Q000235:genetics* / Q000378:metabolism; D000096923:Frataxin
chemical_list: D033862:Iron-Binding Proteins; D024101:Mitochondrial Proteins; D000096923:Frataxin