title: A SUF Fe-S cluster biogenesis system in the mitochondrion-related organelles of the anaerobic protist Pygsuia.
abstract: BACKGROUND
  Many microbial eukaryotes have evolved anaerobic alternatives to mitochondria known as mitochondrion-related organelles (MROs). Yet, only a few of these have been experimentally investigated. Here we report an RNA-seq-based reconstruction of the MRO proteome of Pygsuia biforma, an anaerobic representative of an unexplored deep-branching eukaryotic lineage.
  
  
  RESULTS
  Pygsuia's MRO has a completely novel suite of functions, defying existing "function-based" organelle classifications. Most notable is the replacement of the mitochondrial iron-sulfur cluster machinery by an archaeal sulfur mobilization (SUF) system acquired via lateral gene transfer (LGT). Using immunolocalization in Pygsuia and heterologous expression in yeast, we show that the SUF system does indeed localize to the MRO. The Pygsuia MRO also possesses a unique assemblage of features, including: cardiolipin, phosphonolipid, amino acid, and fatty acid metabolism; a partial Kreb's cycle; a reduced respiratory chain; and a laterally acquired rhodoquinone (RQ) biosynthesis enzyme. The latter observation suggests that RQ is an electron carrier of a fumarate reductase-type complex II in this MRO.
  
  
  CONCLUSIONS
  The unique functional profile of this MRO underscores the tremendous plasticity of mitochondrial function within eukaryotes and showcases the role of LGT in forging metabolic mosaics of ancestral and newly acquired organellar pathways.
authors.affiliation: Centre for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie University, Halifax, NS B3H 4R2, Canada; Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada.
authors.forename: Courtney W
authors.initials: CW
authors.lastname: Stairs
authors.affiliation: Centre for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie University, Halifax, NS B3H 4R2, Canada; Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada.
authors.forename: Laura
authors.initials: L
authors.lastname: Eme
authors.affiliation: Department of Biological Sciences, Mississippi State University, Mississippi State, MS 39762, USA; The Institute for Genomics, Biocomputing, and Biotechnology, Mississippi State University, Mississippi State, MS 39762, USA.
authors.forename: Matthew W
authors.initials: MW
authors.lastname: Brown
authors.affiliation: Centre for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie University, Halifax, NS B3H 4R2, Canada; Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada.
authors.forename: Cornelis
authors.initials: C
authors.lastname: Mutsaers
authors.affiliation: Centre for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie University, Halifax, NS B3H 4R2, Canada; Department of Mathematics and Statistics, Dalhousie University, Halifax, NS B3H 4R2, Canada.
authors.forename: Edward
authors.initials: E
authors.lastname: Susko
authors.affiliation: Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada; Department of Pathology, Dalhousie University, Halifax, NS B3H 4R2, Canada.
authors.forename: Graham
authors.initials: G
authors.lastname: Dellaire
authors.affiliation: Biosciences, University of Exeter, Exeter EX4 4QD, UK.
authors.forename: Darren M
authors.initials: DM
authors.lastname: Soanes
authors.affiliation: Biosciences, University of Exeter, Exeter EX4 4QD, UK.
authors.forename: Mark
authors.initials: M
authors.lastname: van der Giezen
authors.affiliation: Centre for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie University, Halifax, NS B3H 4R2, Canada; Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada. Electronic address: andrew.roger@dal.ca.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Roger
mesh_terms: D000693:Anaerobiosis; D056890:Eukaryota / Q000235:genetics* / Q000378:metabolism*; D008969:Molecular Sequence Data; D015388:Organelles / Q000378:metabolism*; D010802:Phylogeny; D020543:Proteome; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D017423:Sequence Analysis, RNA; D013455:Sulfur / Q000378:metabolism*
chemical_list: D020543:Proteome; D013455:Sulfur