The enzyme contains a tightly but noncovalently bound NADP(H) cofactor, as well as Zn2+ and Mg2+. Enzyme-bound NADPH formed by oxidation of formaldehyde to formate is oxidized back to NADP+ by reaction with a second formaldehyde, yielding methanol. The enzyme from the bacterium Mycobacterium sp. DSM 3803 also catalyses the reactions of EC 1.1.99.36, alcohol dehydrogenase (nicotinoprotein) and EC 1.1.99.37, methanol dehydrogenase (nicotinoprotein) [3]. Formaldehyde and acetaldehyde can act as donors; formaldehyde, acetaldehyde and propanal can act as acceptors [1,2].