title: Complete circular DNA in the mitochondria-like organelles of Blastocystis hominis.
abstract: Blastocystis hominis is an anaerobic parasite of the human intestinal tract belonging to the Stramenopile group. Using genome sequencing project data, we describe here the complete sequence of a 29,270-bp circular DNA molecule that presents mitochondrial features (such as oxidative phosphorylation complex I subunits) but lacks complexes III, IV and V. Transmission electron microscopy analyses reveal that this molecule, as well as mitochondrial (NADH:ubiquinone oxidoreductase subunit 7 (NAD7), beta-succinyl-CoA synthetase (beta-SCS)) and hydrogenosomal (pyruvate ferredoxin oxido-reductase (PFOR), iron-hydrogenase) proteins, are located within double-membrane surrounded-compartments known as mitochondria-like organelles (MLOs). As there is no evidence for hydrogen production by this organism, we suggest that MLOs are more likely anaerobic mitochondria.
authors.affiliation: Laboratoire Microorganismes, Génome et Environnement, UMR CNRS 6023, Université Blaise Pascal, 63177 Aubière Cedex, France.
authors.forename: Ivan
authors.initials: I
authors.lastname: Wawrzyniak
authors.forename: Michaël
authors.initials: M
authors.lastname: Roussel
authors.forename: Marie
authors.initials: M
authors.lastname: Diogon
authors.forename: Arnaud
authors.initials: A
authors.lastname: Couloux
authors.forename: Catherine
authors.initials: C
authors.lastname: Texier
authors.forename: Kevin S W
authors.initials: KS
authors.lastname: Tan
authors.forename: Christian P
authors.initials: CP
authors.lastname: Vivarès
authors.forename: Frédéric
authors.initials: F
authors.lastname: Delbac
authors.forename: Patrick
authors.initials: P
authors.lastname: Wincker
authors.forename: Hicham
authors.initials: H
authors.lastname: El Alaoui
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000378:metabolism*; D016845:Blastocystis hominis / Q000235:genetics* / Q000378:metabolism; D004270:DNA, Circular / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D006864:Hydrogenase / Q000378:metabolism; D007506:Iron-Sulfur Proteins / Q000378:metabolism; D008928:Mitochondria / Q000235:genetics* / Q000378:metabolism; D015388:Organelles / Q000235:genetics* / Q000378:metabolism; D017422:Sequence Analysis, DNA
chemical_list: D001426:Bacterial Proteins; D004270:DNA, Circular; D007506:Iron-Sulfur Proteins; C118830:iron hydrogenase; D006864:Hydrogenase