Butanol dehydrogenase catalyzes the conversion of butyraldehyde to butanol with the cofactor NAD(P)H being oxidized in the process
The butanol dehydrogenase (BDH) is involved in the final step of the butanol formation pathway in anaerobic micro-organism. Butanol dehydrogenase catalyzes the conversion of butyraldehyde to butanol with the cofactor NAD(P)H being oxidized in the process. Activity in the reverse direction is 50-fold lower than that in the forward direction. The NADH-BDH has higher activity with longer chained aldehydes and is inhibited by metabolites containing an adenine moiety. This protein family belongs to the so-called iron-containing alcohol dehydrogenase superfamily. Since members of this superfamily use different divalent ions, preferentially iron or zinc, it has been suggested to be renamed to family III metal-dependent polyol dehydrogenases. This family also includes E. coli YqhD enzyme, an NADP-dependent dehydrogenase whose activity measurements with several alcohols demonstrate preference for alcohols longer than C3. The active site of YqhD contains a Zn metal, and a modified NADPH cofactor bearing OH groups on the saturated C5 and C6 atoms, possibly due to oxygen stress on the enzyme, which would functionally work under anaerobic conditions.