Abstract
An NAD(P)H-nicotine blue (quinone) oxidoreductase was discovered as a member of the nicotine catabolic pathway of Arthrobacter nicotinovorans. Transcriptional analysis and electromobility shift assays showed that the enzyme gene was expressed in a nicotine-dependent manner under the control of the transcriptional activator PmfR and thus was part of the nicotine regulon of A. nicotinovorans. The flavin mononucleotide-containing enzyme uses NADH and, with lower efficiency, NADPH to reduce, by a two-electron transfer, nicotine blue to the nicotine blue leuco form (hydroquinone). Besides nicotine blue, several other quinones were reduced by the enzyme. The NAD(P)H-nicotine blue oxidoreductase may prevent intracellular one-electron reductions of nicotine blue which may lead to semiquinone radicals and potentially toxic reactive oxygen species.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Arthrobacter / enzymology
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Arthrobacter / genetics
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Arthrobacter / physiology*
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Cloning, Molecular
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Coenzymes / pharmacology
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Electron Spin Resonance Spectroscopy
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Flavin Mononucleotide / pharmacology
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Gene Expression Regulation, Bacterial / physiology
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Hydroquinones / metabolism
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Models, Biological
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NAD / metabolism
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NADP / metabolism
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Nicotine / metabolism*
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Oxidation-Reduction
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Oxidative Stress*
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Quinone Reductases / genetics*
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Quinone Reductases / isolation & purification
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Quinone Reductases / metabolism*
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Quinone Reductases / physiology
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RNA, Bacterial / biosynthesis
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RNA, Bacterial / genetics
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RNA, Messenger / biosynthesis
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RNA, Messenger / genetics
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Regulon*
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Substrate Specificity
Substances
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Coenzymes
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Hydroquinones
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RNA, Bacterial
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RNA, Messenger
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NAD
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NADP
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Nicotine
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Flavin Mononucleotide
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Quinone Reductases
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hydroquinone