title: Characterization of a novel angular dioxygenase from fluorene-degrading Sphingomonas sp. strain LB126.
abstract: In this study, the genes involved in the initial attack on fluorene by Sphingomonas sp. strain LB126 were investigated. The alpha and beta subunits of a dioxygenase complex (FlnA1-FlnA2), showing 63 and 51% sequence identity, respectively, to the subunits of an angular dioxygenase from the gram-positive dibenzofuran degrader Terrabacter sp. strain DBF63, were identified. When overexpressed in Escherichia coli, FlnA1-FlnA2 was responsible for the angular oxidation of fluorene, 9-hydroxyfluorene, 9-fluorenone, dibenzofuran, and dibenzo-p-dioxin. Moreover, FlnA1-FlnA2 was able to oxidize polycyclic aromatic hydrocarbons and heteroaromatics, some of which were not oxidized by the dioxygenase from Terrabacter sp. strain DBF63. The quantification of resulting oxidation products showed that fluorene and phenanthrene were the preferred substrates of FlnA1-FlnA2.
authors.affiliation: Unité de Génie Biologique, Institut des Sciences de la Vie, Université Catholique de Louvain, Place Croix du Sud, 2/19, B-1348 Louvain-la-Neuve, Belgium.
authors.forename: Luc
authors.initials: L
authors.lastname: Schuler
authors.forename: Sinéad M
authors.initials: SM
authors.lastname: Ní Chadhain
authors.forename: Yves
authors.initials: Y
authors.lastname: Jouanneau
authors.forename: Christine
authors.initials: C
authors.lastname: Meyer
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: D001483:Base Sequence; D015139:Blotting, Southern; D017931:DNA Primers / Q000235:genetics; D049308:Dioxygenases / Q000235:genetics* / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D005449:Fluorenes / Q000378:metabolism*; D008401:Gas Chromatography-Mass Spectrometry; D008969:Molecular Sequence Data; D015394:Molecular Structure; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D020578:Sphingomonas / Q000201:enzymology*
chemical_list: D017931:DNA Primers; D005449:Fluorenes; C041509:fluorene; D049308:Dioxygenases