title: Molecular organization, biochemical function, cellular role and evolution of NfuA, an atypical Fe-S carrier.
abstract: Biosynthesis of iron-sulphur (Fe-S) proteins is catalysed by multi-protein systems, ISC and SUF. However, 'non-ISC, non-SUF' Fe-S biosynthesis factors have been described, both in prokaryotes and eukaryotes. Here we report in vitro and in vivo investigations of such a 'non-ISC, non SUF' component, the Nfu proteins. Phylogenomic analysis allowed us to define four subfamilies. Escherichia coli NfuA is within subfamily II. Most members of this subfamily have a Nfu domain fused to a 'degenerate' A-type carrier domain (ATC*) lacking Fe-S cluster co-ordinating Cys ligands. The Nfu domain binds a [4Fe-4S] cluster while the ATC* domain interacts with NuoG (a complex I subunit) and aconitase B (AcnB). In vitro, holo-NfuA promotes maturation of AcnB. In vivo, NfuA is necessary for full activity of complex I under aerobic growth conditions, and of AcnB in the presence of superoxide. NfuA receives Fe-S clusters from IscU/HscBA and SufBCD scaffolds and eventually transfers them to the ATCs IscA and SufA. This study provides significant information on one of the Fe-S biogenesis factors that has been often used as a building block by ISC and/or SUF synthesizing organisms, including bacteria, plants and animals.
authors.affiliation: Laboratoire de Chimie Bactérienne, UMR 7283 Aix-Marseille Université-CNRS, Institut de Microbiologie de la Méditerranée, 31 Chemin Joseph Aiguier, 13009 Marseille, France.
authors.forename: Béatrice
authors.initials: B
authors.lastname: Py
authors.forename: Catherine
authors.initials: C
authors.lastname: Gerez
authors.forename: Sandra
authors.initials: S
authors.lastname: Angelini
authors.forename: Rémy
authors.initials: R
authors.lastname: Planel
authors.forename: Daniel
authors.initials: D
authors.lastname: Vinella
authors.forename: Laurent
authors.initials: L
authors.lastname: Loiseau
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Talla
authors.forename: Céline
authors.initials: C
authors.lastname: Brochier-Armanet
authors.forename: Ricardo
authors.initials: R
authors.lastname: Garcia Serres
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Latour
authors.forename: Sandrine
authors.initials: S
authors.lastname: Ollagnier-de Choudens
authors.forename: Marc
authors.initials: M
authors.lastname: Fontecave
authors.forename: Frédéric
authors.initials: F
authors.lastname: Barras
mesh_terms: D000154:Aconitate Hydratase / Q000378:metabolism; D042967:Electron Transport Complex I / Q000378:metabolism; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism*; D007506:Iron-Sulfur Proteins / Q000235:genetics* / Q000378:metabolism*; D010802:Phylogeny; D011485:Protein Binding; D025941:Protein Interaction Mapping; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid
chemical_list: D029968:Escherichia coli Proteins; D007506:Iron-Sulfur Proteins; C529800:NfuA protein, E coli; C556264:NuoG protein, E coli; D000154:Aconitate Hydratase; D042967:Electron Transport Complex I