The Escherichia coli azoreductase AzoR Is involved in resistance to thiol-specific stress caused by electrophilic quinones.
The physiological role of Escherichia coli azoreductase AzoR was studied. It was found that AzoR was capable of reducing several benzo-, naphtho-, and anthraquinone compounds, which were better substrates for AzoR than the model azo substrate methyl red. The DeltaazoR mutant displayed reduced viability when exposed to electrophilic quinones, which are capable of depleting cellular reduced glutathione (GSH). Externally added GSH can partially restore the impaired growth of the DeltaazoR mutant caused by 2-methylhydroquinone. The transcription of azoR was induced by electrophiles, including 2-methylhydroquinone, catechol, menadione, and diamide. A transcription start point was identified 44 bp upstream from the translation start point. These data indicated that AzoR is a quinone reductase providing resistance to thiol-specific stress caused by electrophilic quinones.
Liu
Guangfei
G
Key Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education, School of Environmental andBiological Science and Technology, Dalian University of Technology, Dalian 116024, China.
Zhou
Jiti
J
Fu
Q Shiang
QS
Wang
Jing
J
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D024901:Drug Resistance, Multiple, Bacterial; D004926:Escherichia coli / Q000187:drug effects* / Q000201:enzymology*; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects*; D009154:Mutation; D009247:NADH, NADPH Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D009601:Nitroreductases; D011809:Quinones / Q000494:pharmacology*; D013438:Sulfhydryl Compounds / Q000494:pharmacology*; D014158:Transcription, Genetic
D000900:Anti-Bacterial Agents; D011809:Quinones; D013438:Sulfhydryl Compounds; D009247:NADH, NADPH Oxidoreductases; D009601:Nitroreductases; C021106:azoreductase