The reaction is catalyzed by 3,5-dihydro-5-methyldiene-4H-imidazol-4-one (MIO), an electrophilic cofactor which is formed autocatalytically by cyclization of the protein backbone of the enzyme.
The reaction is driven by 3,5-dihydro-5-methylidene-4H-imidazol-4-one (MIO), an electrophilic catalyst formed through the spontaneous cyclization of the enzyme's peptide backbone.