title: Orthric Rieske dioxygenases for degrading mixtures of 2,4-dinitrotoluene/naphthalene and 2-amino-4,6-dinitrotoluene/4-amino-2,6-dinitrotoluene.
abstract: Pollutants are frequently found as mixtures yet it is difficult to engineer enzymes with broad substrate ranges on aromatics. Inspired by the archetypal nitroarene dioxygenase, which shares its electron transport with a salicylate monooxygenase, we have created an innovative and general approach to expand the substrate range of dioxygenase enzymes in a single cell. We have developed here a series of novel, hybrid dioxygenase enzymes that function with a single ferredoxin reductase and ferredoxin that are used to transport two electrons from nicotinamide adenine dinucleotide to the two independent terminal oxygenases. Each independent alpha-oxygenase may then be used simultaneously to create orthric enzymes that degrade mixtures of environmental pollutants. Specifically, we created a hybrid dioxygenase system consisting of naphthalene dioxygenase/dinitrotoluene dioxygenase to simultaneously degrade 2,4-dinitrotoluene and naphthalene (neither enzyme alone had significant activity on both compounds) and dinitrotoluene dioxygenase/nitrobenzene dioxygenase to simultaneously degrade the frequently encountered 2,4,6-trinitrotoluene reduction products 2-amino-4,6-dinitrotoluene and 4-amino-2,6-dinitrotoluene.
authors.affiliation: Artie McFerrin Department of Chemical Engineering, Texas A and M University, College Station, TX 77843-3122, USA.
authors.forename: Brendan G
authors.initials: BG
authors.lastname: Keenan
authors.forename: Thomas K
authors.initials: TK
authors.lastname: Wood
mesh_terms: D000814:Aniline Compounds / Q000378:metabolism*; D004136:Dinitrobenzenes / Q000378:metabolism*; D049308:Dioxygenases / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D050900:Ferredoxin-Nitrite Reductase / Q000235:genetics / Q000378:metabolism; D005288:Ferredoxins / Q000235:genetics / Q000378:metabolism; D009097:Multienzyme Complexes / Q000235:genetics / Q000378:metabolism; D009243:NAD / Q000378:metabolism; D009281:Naphthalenes / Q000378:metabolism*; D010105:Oxygenases / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D013379:Substrate Specificity
chemical_list: D000814:Aniline Compounds; D004136:Dinitrobenzenes; D005288:Ferredoxins; D009097:Multienzyme Complexes; D009281:Naphthalenes; D011994:Recombinant Proteins; D009243:NAD; C035208:2-amino-4,6-dinitrotoluene; C035207:4-amino-2,6-dinitrotoluene; C031721:naphthalene; C016403:2,4-dinitrotoluene; D010105:Oxygenases; D049308:Dioxygenases; C100896:2,4-dinitrotoluene dioxygenase; C038703:naphthalene dioxygenase; D050900:Ferredoxin-Nitrite Reductase