title: Dps-like protein from the hyperthermophilic archaeon Pyrococcus furiosus.
abstract: Oxidative stress is a universal phenomenon experienced by organisms in all domains of life. Proteins like those in the ferritin-like di-iron carboxylate superfamily have evolved to manage this stress. Here we describe the cloning, isolation, and characterization of a Dps-like protein from the hyperthermophilic archaeon Pyrococcus furiosus (PfDps-like). Phylogenetic analysis, primary structure alignments and higher order structural predictions all suggest that the P. furiosus protein is related to proteins within the broad superfamily of ferritin-like di-iron carboxylate proteins. The recombinant PfDps protein self-assembles into a 12 subunit quaternary structure with an outer shell diameter of approximately 10nm and an interior diameter of approximately 5 nm. Dps proteins functionally manage the toxicity of oxidative stress by sequestering intracellular ferrous iron and using it to reduce H(2)O(2) in a two electron process to form water. The iron is converted to a benign form as Fe(III) within the protein cage. This Dps-mediated reduction of hydrogen peroxide, coupled with the protein's capacity to sequester iron, contributes to its service as a multifunctional antioxidant.
authors.affiliation: Thermal Biology Institute, Montana State University, 108 Gaines Hall, Bozeman, MT 59717, USA.
authors.forename: Bradley
authors.initials: B
authors.lastname: Ramsay
authors.forename: Blake
authors.initials: B
authors.lastname: Wiedenheft
authors.forename: Mark
authors.initials: M
authors.lastname: Allen
authors.forename: George H
authors.initials: GH
authors.lastname: Gauss
authors.forename: C Martin
authors.initials: CM
authors.lastname: Lawrence
authors.forename: Mark
authors.initials: M
authors.lastname: Young
authors.forename: Trevor
authors.initials: T
authors.lastname: Douglas
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015153:Blotting, Western; D002850:Chromatography, Gel; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D046529:Microscopy, Electron, Transmission; D008969:Molecular Sequence Data; D010802:Phylogeny; D020027:Pyrococcus furiosus / Q000378:metabolism*; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; C083911:DPS protein, Bacteria; D011994:Recombinant Proteins