Characterization of a transcriptional regulatory gene involved in dibenzofuran degradation by Nocardioides sp. strain DF412.
Nocardioides sp. DF412 degrades dibenzofuran (DF) to salicylate through the sequential actions of DF dioxygenase (dfdA), extradiol dioxygenase (dfdB), and hydrolase (dfdC). The involvement of a TetR-type regulator gene dfdS in the dfdB and dfdS gene expression was investigated. A reporter assay using a luciferase gene indicated repression of dfdB and dfdS promoter activities in the presence of the dfdS gene product, DfdS. Gel shift analysis indicated specific binding of DfdS to the dfdB promoter region. Both the presence of a DF-degradation intermediate, 2,2',3-trihydroxybiphenyl (2,2',3-THBP) or its analog, 2,3-dihydroxybiphenyl (2,3-DHBP), and mutation in the inverted repeat (IR) in the dfdB promoter, canceled repression by DfdS in vivo and the binding of DfdS to the dfdB promoter fragment in vitro. These results suggest derepression of DfdS in the presence of 2,2',3-THBP and 2,3-DHBP and the involvement of the IR in the repression by DfdS.
Sukda
Parichat
P
Department of Bioengineering, Nagaoka University of Technology, Nagaoka, Niigata, Japan.
Gouda
Nao
N
Ito
Emi
E
Miyauchi
Keisuke
K
Masai
Eiji
E
Fukuda
Masao
M
D001483:Base Sequence; D001572:Benzofurans / Q000378:metabolism*; D024202:Electrophoretic Mobility Shift Assay; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D011423:Propionibacteriaceae / Q000235:genetics* / Q000378:metabolism*; D014158:Transcription, Genetic
D001572:Benzofurans; C023614:dibenzofuran