The enzyme produces the modified flavin cofactor prenylated FMNH2, which is required by EC
4.1.1.98, 4-hydroxy-3-polyprenylbenzoate decarboxylase, and EC
4.1.1.102, phenacrylate decarboxylase. The enzyme acts as a flavin prenyltransferase, linking a prenyl moiety to the flavin N-5 and C-6 atoms and thus adding a fourth non-aromatic ring to the flavin isoalloxazine group.