FAD binding domain. This family consists of various enzymes that use FAD as a co-factor, most of the enzymes are similar to oxygen oxidoreductase. One of the enzymes Vanillyl-alcohol oxidase (VAO) has a solved structure, the alignment includes the FAD binding site, called the PP-loop, between residues 99-110. The FAD molecule is covalently bound in the known structure, however the residue that links to the FAD is not in the alignment. VAO catalyzes the oxidation of a wide variety of substrates, ranging form aromatic amines to 4-alkylphenols. Other members of this family include D-lactate dehydrogenase, this enzyme catalyzes the conversion of D-lactate to pyruvate using FAD as a co-factor; mitomycin radical oxidase, this enzyme oxidises the reduced form of mitomycins and is involved in mitomycin resistance. This family includes MurB an UDP-N-acetylenolpyruvoylglucosamine reductase enzyme EC:1.1.1.158. This enzyme is involved in the biosynthesis of peptidoglycan.

FAD/FMN-containing dehydrogenases [Energy production and conversion]

FAD-dependent oxidoreductase; Provisional

plant-specific FAD-dependent oxidoreductase. This model represents an uncharacterized plant-specific family of FAD-dependent oxidoreductases. At least seven distinct members are found in Arabidopsis thaliana. The family shows considerable sequence similarity to three different enzymes of ascorbic acid biosynthesis: L-galactono-1,4-lactone dehydrogenase (EC 1.3.2.3) from higher plants, D-arabinono-1,4-lactone oxidase (EC 1.1.3.37 from Saccharomyces cerevisiae, and L-gulonolactone oxidase (EC 1.1.3.8) from mouse, as well as to a bacterial sorbitol oxidase. The class of compound acted on by members of this family is unknown.