Flavin-containing monooxygenase

The flavin-containing monooxygenase (FMO) protein family consists of a group of enzymes that catalyze chemical reactions via the bound cofactor flavin. These reactions involve oxidation of heteroatoms, particularly nucleophilic atoms such as the nitrogen of amines.

The best-known such protein is called FMO3 and is mutated in the vast majority of cases of trimethylaminuria, a genetic disease that causes deficiencies in breakdown of trimethylamine and gives the patient a fishy body odor. In yeast, FMO proteins are associated with redox cycling of glutathione to glutathione disulfide, a system that maintains the redox state of the cell and heavily influences the protein folding rates of disulfide bond-containing proteins.