Methylamine dehydrogenase carries out the oxidation of methylamine. Electrons are passed from methylamine dehydrogenase to amicyanin. H2O + methylamine + 2 oxidized [amicyanin] = formaldehyde + 2 H(+) + NH4(+) + 2 reduced [amicyanin] Uses a protein-derived tryptophan tryptophylquinone (TTQ) cofactor. One-carbon metabolism; methylamine degradation; formaldehyde from methylamine: step 1/1. Heterotetramer of two light and two heavy chains. Predicted to be exported by the Tat system. The position of the signal peptide cleavage has been experimentally proven. Tryptophan tryptophylquinone (TTQ) is formed by oxidation of the indole ring of a tryptophan to form tryptophylquinone followed by covalent cross-linking with another tryptophan residue. Belongs to the aromatic amine dehydrogenase light chain family.