title: An NAD(P)H-nicotine blue oxidoreductase is part of the nicotine regulon and may protect Arthrobacter nicotinovorans from oxidative stress during nicotine catabolism.
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.
authors.affiliation: Institute of Biochemistry and Molecular Biology, Hermann-Herder-Str 7, 79104 Freiburg, Germany.
authors.forename: Marius
authors.initials: M
authors.lastname: Mihasan
authors.forename: Calin-Bogdan
authors.initials: CB
authors.lastname: Chiribau
authors.forename: Thorsten
authors.initials: T
authors.lastname: Friedrich
authors.forename: Vlad
authors.initials: V
authors.lastname: Artenie
authors.forename: Roderich
authors.initials: R
authors.lastname: Brandsch
mesh_terms: D001173:Arthrobacter / Q000201:enzymology / Q000235:genetics / Q000502:physiology*; D003001:Cloning, Molecular; D003067:Coenzymes / Q000494:pharmacology; D004578:Electron Spin Resonance Spectroscopy; D005486:Flavin Mononucleotide / Q000494:pharmacology; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D006873:Hydroquinones / Q000378:metabolism; D008954:Models, Biological; D009243:NAD / Q000378:metabolism; D009249:NADP / Q000378:metabolism; D009538:Nicotine / Q000378:metabolism*; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D011808:Quinone Reductases / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism* / Q000502:physiology; D012329:RNA, Bacterial / Q000096:biosynthesis / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D018085:Regulon; D013379:Substrate Specificity
chemical_list: D003067:Coenzymes; D006873:Hydroquinones; D012329:RNA, Bacterial; D012333:RNA, Messenger; D009243:NAD; D009249:NADP; D009538:Nicotine; D005486:Flavin Mononucleotide; D011808:Quinone Reductases; C031927:hydroquinone