Function
Methylamine dehydrogenase (MADH) catalyzes the oxidative deamination of primary amine to aldehyde and ammonia, in particular, the conversion of methylamine to formaldehyde. MADH is tryptophan tryptophyl-quinone (TTQ) dependent. MADH is a heterotetramer containing 2 heavy (α) and 2 light (β) subunits. Each β subunit contains a TTQ prosthetic group. The posttranslational modification of two tryptophan residues in preMADH to form the TTQ cofactor of MADH is catalyzed by methylation utilization protein (MauG). MADH forms a complex with cytochrome c-551i. In the complex, electrons are transferred from TTQ via the amicyanin copper ion center to the heme group of cytochrome[1].
Structural highlights
The MADH unique redox center is located in the light subunit[2]. .
