title: Evolutionary conservation and in vitro reconstitution of microsporidian iron-sulfur cluster biosynthesis.
abstract: Microsporidians are obligate intracellular parasites that have minimized their genome content and sub-cellular structures by reductive evolution. Here, we demonstrate that cristae-deficient mitochondria (mitosomes) of Trachipleistophora hominis are the functional site of iron-sulfur cluster (ISC) assembly, which we suggest is the essential task of these organelles. Cell fractionation, fluorescence imaging and immunoelectron microscopy demonstrate that mitosomes contain a complete pathway for [2Fe-2S] cluster biosynthesis that we biochemically reconstituted using purified mitosomal ISC proteins. The T. hominis cytosolic iron-sulfur protein assembly (CIA) pathway includes the essential Cfd1-Nbp35 scaffold complex that assembles a [4Fe-4S] cluster as shown by spectroscopic methods in vitro. Phylogenetic analyses reveal that the ISC and CIA pathways are predominantly bacterial, but their cytosolic and nuclear target Fe/S proteins are mainly archaeal. This mixed evolutionary history of Fe/S-related proteins and pathways, and their strong conservation among highly reduced parasites, provides compelling evidence for the ancient chimeric ancestry of eukaryotes.
authors.affiliation: Institut für Zytobiologie und Zytopathologie, Philipps-Universität, Robert-Koch-Strasse 6, Marburg 35032, Germany.
authors.forename: Sven-A
authors.initials: SA
authors.lastname: Freibert
authors.affiliation: Institute for Cell and Molecular Biosciences, University of Newcastle, Newcastle upon Tyne NE2 4HH, UK.
authors.forename: Alina V
authors.initials: AV
authors.lastname: Goldberg
authors.affiliation: School of Medicine, University of St Andrews, St. Andrews KY16 9TF, UK.|Bioimaging Centre, College of Life and Environmental Sciences, University of Exeter, Stocker Road, Exeter EX4 4QD, UK.
authors.forename: Christian
authors.initials: C
authors.lastname: Hacker
authors.affiliation: Institut für Zytobiologie und Zytopathologie, Philipps-Universität, Robert-Koch-Strasse 6, Marburg 35032, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Molik
authors.affiliation: Institute for Cell and Molecular Biosciences, University of Newcastle, Newcastle upon Tyne NE2 4HH, UK.
authors.forename: Paul
authors.initials: P
authors.lastname: Dean
authors.affiliation: Institute for Cell and Molecular Biosciences, University of Newcastle, Newcastle upon Tyne NE2 4HH, UK.
authors.forename: Tom A
authors.identifier: 0000-0003-1072-0223
authors.initials: TA
authors.lastname: Williams
authors.affiliation: Institute for Cell and Molecular Biosciences, University of Newcastle, Newcastle upon Tyne NE2 4HH, UK.
authors.forename: Sirintra
authors.initials: S
authors.lastname: Nakjang
authors.affiliation: Institute for Cell and Molecular Biosciences, University of Newcastle, Newcastle upon Tyne NE2 4HH, UK.
authors.forename: Shaojun
authors.initials: S
authors.lastname: Long
authors.affiliation: Institute for Cell and Molecular Biosciences, University of Newcastle, Newcastle upon Tyne NE2 4HH, UK.
authors.forename: Kacper
authors.initials: K
authors.lastname: Sendra
authors.affiliation: Max-Planck-Institut für Bioanorganische Chemie, Stiftstrasse 34-36, Mülheim an der Ruhr 45470, Germany.
authors.forename: Eckhard
authors.initials: E
authors.lastname: Bill
authors.affiliation: Institute for Cell and Molecular Biosciences, University of Newcastle, Newcastle upon Tyne NE2 4HH, UK.
authors.forename: Eva
authors.initials: E
authors.lastname: Heinz
authors.affiliation: Institute for Cell and Molecular Biosciences, University of Newcastle, Newcastle upon Tyne NE2 4HH, UK.
authors.forename: Robert P
authors.identifier: 0000-0002-3760-9958
authors.initials: RP
authors.lastname: Hirt
authors.affiliation: School of Medicine, University of St Andrews, St. Andrews KY16 9TF, UK.
authors.forename: John M
authors.initials: JM
authors.lastname: Lucocq
authors.affiliation: Institute for Cell and Molecular Biosciences, University of Newcastle, Newcastle upon Tyne NE2 4HH, UK.
authors.forename: T Martin
authors.initials: TM
authors.lastname: Embley
authors.affiliation: Institut für Zytobiologie und Zytopathologie, Philipps-Universität, Robert-Koch-Strasse 6, Marburg 35032, Germany.|LOEWE Zentrum für Synthetische Mikrobiologie SynMikro, Hans-Meerwein-Strasse, Marburg 35043, Germany.
authors.forename: Roland
authors.identifier: 0000-0002-8345-6518
authors.initials: R
authors.lastname: Lill
mesh_terms: D005075:Biological Evolution; D002467:Cell Nucleus / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D005656:Fungal Proteins / Q000096:biosynthesis* / Q000235:genetics; D007506:Iron-Sulfur Proteins / Q000096:biosynthesis* / Q000235:genetics; D008928:Mitochondria / Q000378:metabolism*; D050175:Pansporablastina / Q000235:genetics / Q000378:metabolism*; D010802:Phylogeny
chemical_list: D005656:Fungal Proteins; D007506:Iron-Sulfur Proteins