title: Characterization of a ring-hydroxylating dioxygenase from phenanthrene-degrading Sphingomonas sp. strain LH128 able to oxidize benz[a]anthracene.
abstract: Sphingomonas sp. strain LH128 was isolated from a polycyclic aromatic hydrocarbon (PAH)-contaminated soil using phenanthrene as the sole source of carbon and energy. A dioxygenase complex, phnA1fA2f, encoding the alpha and beta subunit of a terminal dioxygenase responsible for the initial attack on PAHs, was identified and isolated from this strain. PhnA1f showed 98%, 78%, and 78% identity to the alpha subunit of PAH dioxygenase from Novosphingobium aromaticivorans strain F199, Sphingomonas sp. strain CHY-1, and Sphingobium yanoikuyae strain B1, respectively. When overexpressed in Escherichia coli, PhnA1fA2f was able to oxidize low-molecular-weight PAHs, chlorinated biphenyls, dibenzo-p-dioxin, and the high-molecular-weight PAHs benz[a]anthracene, chrysene, and pyrene. The action of PhnA1fA2f on benz[a]anthracene produced two benz[a]anthracene dihydrodiols.
authors.affiliation: Unité de Génie Biologique, Institut des Sciences de la Vie, Université Catholique de Louvain, Place Croix du Sud, 2/19, 1348 Louvain-la-Neuve, Belgium.
authors.forename: Luc
authors.initials: L
authors.lastname: Schuler
authors.forename: Yves
authors.initials: Y
authors.lastname: Jouanneau
authors.forename: Sinéad M Ní
authors.initials: SM
authors.lastname: Chadhain
authors.forename: Christine
authors.initials: C
authors.lastname: Meyer
authors.forename: Maria
authors.initials: M
authors.lastname: Pouli
authors.forename: Gerben J
authors.initials: GJ
authors.lastname: Zylstra
authors.forename: Pascal
authors.initials: P
authors.lastname: Hols
authors.forename: Spiros N
authors.initials: SN
authors.lastname: Agathos
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D001551:Benz(a)Anthracenes / Q000378:metabolism*; D001673:Biodegradation, Environmental; D049308:Dioxygenases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D010616:Phenanthrenes / Q000378:metabolism*; D011084:Polycyclic Aromatic Hydrocarbons / Q000378:metabolism; D012988:Soil Microbiology; D020578:Sphingomonas / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D013379:Substrate Specificity
chemical_list: D001426:Bacterial Proteins; D001551:Benz(a)Anthracenes; D010616:Phenanthrenes; D011084:Polycyclic Aromatic Hydrocarbons; C031181:phenanthrene; C030935:benz(a)anthracene; D049308:Dioxygenases