Analysis of two gene clusters involved in the degradation of 4-fluorophenol by Arthrobacter sp. strain IF1.
Arthrobacter sp. strain IF1 is able to grow on 4-fluorophenol (4-FP) as a sole source of carbon and energy. To clone the 4-FP degradation genes, DNA libraries were constructed and screened with a probe obtained by PCR using primers designed on the basis of conserved regions of aromatic two-component monooxygenases. Sequencing of positive clones yielded two gene clusters, each harboring a gene encoding a monooxygenase with high sequence similarity to the oxygenase component of 4-nitrophenol and 4-chlorophenol monooxygenase systems. Both these monooxygenase genes were differentially expressed during growth on 4-FP, as revealed by Northern blotting and reverse transcription-PCR. One cluster also contained a gene for a flavin reductase. The monooxygenase and reductase were purified from Escherichia coli cells expressing the corresponding genes, and together they catalyzed NADH-dependent hydroxylation and dehalogenation of 4-halophenols. The results indicate that strain IF1 transforms 4-FP to hydroquinone by a two-component monooxygenase system of which one component provides reduced flavin adenine dinucleotide at the expense of NADH and the other catalyzes para-hydroxylation of 4-FP and other 4-substituted phenols.
Ferreira
Maria Isabel M
MI
Department of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, NL-9747 AG Groningen, The Netherlands.
Iida
Toshiya
T
Hasan
Syed A
SA
Nakamura
Kaoru
K
Fraaije
Marco W
MW
Janssen
Dick B
DB
Kudo
Toshiaki
T
D001173:Arthrobacter / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism*; D001673:Biodegradation, Environmental; D004785:Environmental Pollutants / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D005810:Multigene Family; D010105:Oxygenases / Q000235:genetics* / Q000378:metabolism; D010636:Phenols / Q000378:metabolism*
D004785:Environmental Pollutants; D010636:Phenols; C106880:4-fluorophenol; D010105:Oxygenases; C020066:dimethylaniline monooxygenase (N-oxide forming)