Acireductone dioxygenase (iron(II)-requiring)

Acireductone dioxygenase [iron(II)-requiring] () is an enzyme that catalyzes the chemical reaction

:1,2-dihydroxy-5-(methylthio)pent-1-en-3-one + O2 \rightleftharpoons 4-(methylthio)-2-oxobutanoate + formate

Thus, the two substrates of this enzyme are 1,2-dihydroxy-5-(methylthio)pent-1-en-3-one and oxygen, whereas its two products are 4-methylthio-2-oxobutanoate and formate.

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-forming). Other names in common use include **ARD'''', 2-hydroxy-3-keto-5-thiomethylpent-1-ene dioxygenase (ambiguous), acireductone dioxygenase (ambiguous), E-2', and **E-3 dioxygenase'''. This enzyme participates in methionine metabolism.