Acireductone dioxygenase (Ni2 requiring)

Acireductone dioxygenase (Ni2+-requiring) (EC 1.13.11.53) is an enzyme that catalyzes the chemical reaction

1,2-dihydroxy-5-(methylthio)pent-1-en-3-one + O₂ ⇌ 3-(methylthio)propanoate + formate + CO

Thus, the two substrates of this enzyme are 1,2-dihydroxy-5-(methylthio)pent-1-en-3-one and oxygen, whereas its 3 products are 3-(methylthio)propanoate, formate, and carbon monoxide.

This enzyme belongs to the family of oxidoreductases, specifically those acting on single donors with O₂ as oxidant and incorporation of two atoms of oxygen into the substrate (oxygenases). The oxygen incorporated need not be derived from O₂. The systematic name of this enzyme class is 1,2-dihydroxy-5-(methylthio)pent-1-en-3-one:oxygen oxidoreductase (formate- and CO-forming). Other names in common use include ARD, 2-hydroxy-3-keto-5-thiomethylpent-1-ene dioxygenase (ambiguous), acireductone dioxygenase (ambiguous), and E-2. This enzyme participates in methionine metabolism.