title: Iron homeostasis and responses to iron limitation in extreme acidophiles from the Ferroplasma genus.
abstract: Extremely acidophilic archaea from the genus Ferroplasma inhabit iron-rich biomining environments and are important constituents of naturally occurring microbial consortia that catalyze the production of acid mine drainage. A combined bioinformatic, transcript profiling, and proteomic approach was used to elucidate iron homeostasis mechanisms in "F. acidarmanus" Fer1 and F. acidiphilum Y(T) . Bioinformatic analysis of the "F. acidarmanus" Fer1 genome sequence revealed genes encoding proteins hypothesized to be involved in iron-dependent gene regulation and siderophore biosynthesis; the Fhu and NRAMP cation acquisition systems; iron storage proteins; and the SUF machinery for the biogenesis of Fe-S clusters. A subset of homologous genes was identified on the F. acidiphilum Y(T) chromosome by direct PCR probing. In both strains, some of the genes appeared to be regulated in a ferrous/ferric iron-dependent manner, as indicated by RT-PCR. A detailed gel-based proteomics analysis of responses to iron depletion showed that a putative isochorismatase, presumably involved in siderophore biosynthesis, and the SufBCD system were upregulated under iron-limiting conditions. No evidence was obtained for iron sparing response during iron limitation. This study constitutes the first detailed investigation of iron homeostasis in extremely acidophilic archaea.
authors.affiliation: Department of Molecular Biology, Umeå University, Umeå, Sweden. j.potrykus@abdn.ac.uk
authors.forename: Joanna
authors.initials: J
authors.lastname: Potrykus
authors.forename: Venkateswara Rao
authors.initials: VR
authors.lastname: Jonna
authors.forename: Mark
authors.initials: M
authors.lastname: Dopson
mesh_terms: D019295:Computational Biology / Q000379:methods; D006706:Homeostasis / Q000502:physiology; D007501:Iron / Q000378:metabolism*; D040901:Proteomics / Q000379:methods*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019603:Thermoplasmales / Q000378:metabolism*
chemical_list: D007501:Iron