Fig 1.

Methanol and methylamine oxidation pathway. Gene products involved in each reaction are indicated next to the arrows. Abbreviations: HCHO, formaldehyde; MDH, methanol dehydrogenase; MaDH, methylamine dehydrogenase; dH₄MPT, dephosphotetrahydromethanopterin; Fae, formaldehyde-activating enzyme; CH₂=dH₄MPT, methylene-dH₄MPT; MtdB and MtdA, methylene-tetrahydromethanopterin dehydrogenases; CHdH₄MPT, methenyl-dephosphoH₄MPT; Mch, methenyl-dH₄MPT cyclohydrolase; CHO—dH₄MPT, formyl-dH₄MPT; Fhc, formyltransferase/hydrolase complex; Fdh, formate dehydrogenase; FtfL, formate-tetrahydrofolate ligase; H₄F, tetrahydrofolate; CHO—H₄F, to formyl-H₄F; Fch, methenyl-H₄F cyclohydrolase; CHH₄F, methenyl-H₄F; CH₂—H₄F, methylene-H₄F; GSH, glutathione; GMA synthetase, gamma-glutamylmethylamide synthetase; NMG synthase, N-methyl glutamate synthase; NMG dehydrogenase, N-methyl glutamate dehydrogenase; FlhA, GSH/NAD-dependent formaldehyde dehydrogenase; FghA, S-formyl-GSH hydrolase. The dashed line represents the proposed NMG pathway, where “(i)” represents gamma-glutamylmethylamide and “(ii)” represents N-methyl glutamate. Gray lines represent the heterologous Paracoccus denitrificans formaldehyde detoxification pathway encoded on the plasmid pCM106 (16).