Flavin adenine dinucleotide synthase (FADS)

Flavin adenine dinucleotide synthase is an essential enzyme responsible for catalyzing the final step in the biosynthesis of flavin adenine dinucleotide (FAD) from flavin mononucleotide (FMN) by transferring an adenylyl group from ATP to FMN. This bifunctional protein exhibits both adenylyltransferase activity—forming FAD—and pyrophosphatase activity—regulating nucleotide pools. The human gene encoding this enzyme is called FLAD1. The protein localizes primarily in mitochondria and cytosol but has also been detected in nuclei, supporting critical roles across subcellular compartments. FADS ensures adequate supply of FAD, a vital redox-active cofactor required by numerous flavoenzymes involved in key metabolic pathways such as oxidative phosphorylation, fatty acid oxidation, amino acid catabolism, and other redox reactions essential for cellular energy production. Deficiencies or mutations affecting this enzyme result in severe metabolic disorders including lipid storage myopathy due to impaired electron transfer within mitochondria, highlighting its importance for human health. There are no approved drugs that directly modulate this enzyme's function; however, riboflavin supplementation may be used therapeutically when genetic defects impair endogenous synthesis upstream or at the level of FLAD1/FADS itself.

Other names

FAD synthetaseFlavin adenine dinucleotide synthetaseFLAD1 (gene name)FAD-SynthetaseEC 2.7.7.2FMN adenylyltransferase

Not applicable for direct drug targeting; the enzyme catalyzes the conversion of FMN to FAD using ATP as a cofactor. Riboflavin supplementation increases substrate availability for this pathway.