title: Functional reconstitution of mitochondrial Fe/S cluster synthesis on Isu1 reveals the involvement of ferredoxin.
abstract: Maturation of iron-sulphur (Fe/S) proteins involves complex biosynthetic machinery. In vivo synthesis of [2Fe-2S] clusters on the mitochondrial scaffold protein Isu1 requires the cysteine desulphurase complex Nfs1-Isd11, frataxin, ferredoxin Yah1 and its reductase Arh1. The roles of Yah1-Arh1 have remained enigmatic, because they are not required for in vitro Fe/S cluster assembly. Here, we reconstitute [2Fe-2S] cluster synthesis on Isu1 in a reaction depending on Nfs1-Isd11, frataxin, Yah1, Arh1 and NADPH. Unlike in the bacterial system, frataxin is an essential part of Fe/S cluster biosynthesis and is required simultaneously and stoichiometrically to Yah1. Reduced but not oxidized Yah1 tightly interacts with apo-Isu1 indicating a dynamic interaction between Yah1-apo-Isu1. Nuclear magnetic resonance structural studies identify the Yah1-apo-Isu1 interaction surface and suggest a pathway for electron flow from reduced ferredoxin to Isu1. Together, our study defines the molecular function of the ferredoxin Yah1 and its human orthologue FDX2 in mitochondrial Fe/S cluster synthesis.
authors.affiliation: Institut für Zytobiologie und Zytopathologie, Philipps-Universität Marburg, Robert-Koch-Strasse 6, 35032 Marburg, Germany.
authors.forename: Holger
authors.initials: H
authors.lastname: Webert
authors.affiliation: Institut für Zytobiologie und Zytopathologie, Philipps-Universität Marburg, Robert-Koch-Strasse 6, 35032 Marburg, Germany.
authors.forename: Sven-Andreas
authors.initials: SA
authors.lastname: Freibert
authors.affiliation: CERM, Magnetic Resonance Center, University of Florence, Sesto Fiorentino, 50019 Florence, Italy.
authors.forename: Angelo
authors.initials: A
authors.lastname: Gallo
authors.affiliation: Institut für Zytobiologie und Zytopathologie, Philipps-Universität Marburg, Robert-Koch-Strasse 6, 35032 Marburg, Germany.
authors.forename: Torsten
authors.initials: T
authors.lastname: Heidenreich
authors.affiliation: Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Street, 35043 Marburg, Germany.
authors.forename: Uwe
authors.initials: U
authors.lastname: Linne
authors.affiliation: Biochemie-Zentrum Heidelberg (BZH), Im Neuenheimer Feld 328, 69120 Heidelberg, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Amlacher
authors.affiliation: Biochemie-Zentrum Heidelberg (BZH), Im Neuenheimer Feld 328, 69120 Heidelberg, Germany.
authors.forename: Ed
authors.initials: E
authors.lastname: Hurt
authors.affiliation: Institut für Zytobiologie und Zytopathologie, Philipps-Universität Marburg, Robert-Koch-Strasse 6, 35032 Marburg, Germany.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Mühlenhoff
authors.affiliation: 1] CERM, Magnetic Resonance Center, University of Florence, Sesto Fiorentino, 50019 Florence, Italy [2] Department of Chemistry, University of Florence, Via della Lastruccia 3, Sesto Fiorentino, 50019 Florence, Italy.
authors.forename: Lucia
authors.initials: L
authors.lastname: Banci
authors.affiliation: 1] Institut für Zytobiologie und Zytopathologie, Philipps-Universität Marburg, Robert-Koch-Strasse 6, 35032 Marburg, Germany [2] Max-Planck-Institut für terrestrische Mikrobiologie, Karl-von-Frisch-Street 10, 35043 Marburg, Germany [3] LOEWE Zentrum für Synthetische Mikrobiologie SynMikro, Hans-Meerwein-Street, 35043 Marburg, Germany.
authors.forename: Roland
authors.initials: R
authors.lastname: Lill
mesh_terms: D000325:Adrenodoxin / Q000737:chemistry / Q000378:metabolism*; D055162:Biocatalysis; D002597:Chaetomium; D004926:Escherichia coli; D005287:Ferredoxin-NADP Reductase / Q000378:metabolism; D005288:Ferredoxins / Q000378:metabolism; D006801:Humans; D007506:Iron-Sulfur Proteins / Q000096:biosynthesis*; D008565:Membrane Proteins / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism; D024101:Mitochondrial Proteins / Q000737:chemistry / Q000378:metabolism*; D012441:Saccharomyces cerevisiae; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000378:metabolism*; D013466:Sulfurtransferases / Q000378:metabolism
chemical_list: D005288:Ferredoxins; C121520:ISU1 protein, S cerevisiae; D007506:Iron-Sulfur Proteins; C508374:Isd11 protein, S cerevisiae; D008565:Membrane Proteins; D024101:Mitochondrial Proteins; D029701:Saccharomyces cerevisiae Proteins; C120375:YAH1 protein, S cerevisiae; D000325:Adrenodoxin; C492747:Arh1 protein, S cerevisiae; D005287:Ferredoxin-NADP Reductase; D013466:Sulfurtransferases; C115912:NFS1 protein, S cerevisiae