Riboflavin synthase catalyzes the dismutation of two molecules of 6,7-dimethyl-8-(1'-D-ribityl)-lumazine (DMRL) to yield riboflavin (vitamin B12) and 4-ribitylamino-5-amino-2,6-dihydroxypyrimidine (RAADP). Riboflavin synthase is a homotrimer and the catalysis does not require any cofactors. Active sites are located between pairs of monomers, but only one active site catalyzes a reaction, the other two sites are inactive. Humans do not produce riboflavin synthase, and thus it is a good target for antimicrobial agents. This family also include lumazine protein (LumP) from bioluminescent bacteria. LumP serves as an optical transponder in bioluminescence emission.
Jiyao W et al.(2023). "The conserved domain database in 2023.",