title: Reduction of U(VI) by the deep subsurface bacterium, Thermus scotoductus SA-01, and the involvement of the ABC transporter protein.
abstract: In this study we investigated the effect of uranium on the growth of the bacterium Thermus scotoductus strain SA-01 as well as the whole cell U(VI) reduction capabilities of the organism. Also, site-directed mutagenesis confirmed the identity of a protein capable of a possible alternative mechanism of U(VI) reduction. SA-01 can grow aerobically in up to 1.25 mM uranium and has the capability to reduce low levels of U(VI) in under 20 h. TEM analysis performed on cells exposed to uranium showed extracellular and membrane-bound accumulation of uranium. The reductase-like protein was surprisingly identified as a peptide ABC transporter, peptide-binding protein. This study showcases the concept of protein promiscuity, where this protein with a distinct function in situ can also have the unintended function of a reactant for the reduction of U(VI).
authors.affiliation: Department of Microbial, Biochemical and Food Biotechnology, University of the Free State, Bloemfontein 9300, South Africa.
authors.forename: Errol Duncan
authors.initials: ED
authors.lastname: Cason
authors.forename: Lizelle Ann
authors.initials: LA
authors.lastname: Piater
authors.forename: Esta
authors.initials: E
authors.lastname: van Heerden
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001673:Biodegradation, Environmental; D004579:Electron Transport; D004785:Environmental Pollutants / Q000302:isolation & purification / Q000378:metabolism* / Q000633:toxicity; D008958:Models, Molecular; D009154:Mutation; D010088:Oxidoreductases / Q000302:isolation & purification / Q000378:metabolism; D011487:Protein Conformation; D013824:Thermus / Q000166:cytology / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D014501:Uranium / Q000302:isolation & purification / Q000378:metabolism* / Q000633:toxicity
chemical_list: D018528:ATP-Binding Cassette Transporters; D001426:Bacterial Proteins; D004785:Environmental Pollutants; D014501:Uranium; D010088:Oxidoreductases