Protocatechuate 3,4-dioxygenase

In enzymology, a protocatechuate 3,4-dioxygenase is an enzyme that catalyzes the chemical reaction


 * 3,4-dihydroxybenzoate + O2 $$\rightleftharpoons$$ 3-carboxy-cis,cis-muconate

Thus, the two substrates of this enzyme are 3,4-dihydroxybenzoate and O2, whereas its product is 3-carboxy-cis,cis-muconate.

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 protocatechuate:oxygen 3,4-oxidoreductase (decyclizing). Other names in common use include protocatechuate oxygenase, protocatechuic acid oxidase, protocatechuic 3,4-dioxygenase, and protocatechuic 3,4-oxygenase. This enzyme participates in benzoate degradation via hydroxylation and 2,4-dichlorobenzoate degradation. It employs one cofactor, iron.

Structural studies
As of late 2007, 37 structures have been solved for this class of enzymes, with PDB accession codes, , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , and.