Alcohol dehydrogenase class-3 (ADH5) is a cytosolic dimeric enzyme that binds 2 Zn2+ per subunit. It is very ineffective in oxidising ethanol, but it readily catalyses the oxidation of S-(hydroxymethyl) glutathione (S-HMGSH) to S-formylglutathione (S-FGSH) (Kaiser et al. 1988, Julia et al. 1988) as well as the oxidation of long-chain primary alcohols (not shown here).