Figure 1.

The pyridine pathway of nicotine degradation by A. nicotinovorans and Nocardioides sp. NDH, nicotine dehydrogenase; 6-HLNO, 6-hydroxy-L-nicotine oxidase; 6HDNO, 6-hydroxy-D-nicotine oxidase; KO, ketone oxidase; KDH, ketone dehydrogenase; 2,6-DHPONH, 2-6-dihyroxypseudooxynicotine hydrolase; 2,6-DHPH, 2,6-dihydroxypyridine-3-hydroxylase; MABO, γ-N-methylaminobutyrate oxidase; MAO, monoamine oxidase; AO, amine oxidase; FolD, methylenetetrahydrofolate dehydrogenase/cyclohydrolase; PurU, formyltetrahydrofolate deformylase; SsaDH, succinic semialdehyde dehydrogenase.