Methylamine dehydrogenase (EC:1.4.99.3) a periplasmic quinoprotein found in several methyltrophic bacteria. Induced when grown on methylamine as a carbon source MADH catalyses the oxidative deamination of amines to there corresponding aldehydes. MADH is a hetero- tetramer, comprised of two heavy chains (H) and two light chains (L). The H-chain forms a beta-propeller like structure [1].

1: Refined crystal structure of methylamine dehydrogenase from Paracoccus denitrificans at 1.75 A resolution. Chen L, Doi M, Durley RC, Chistoserdov AY, Lidstrom ME, Davidson VL, Mathews FS; J Mol Biol 1998;276:131-149. PMID:9514722