4-carboxymuconolactone decarboxylase

In enzymology, a 4-carboxymuconolactone decarboxylase () is an enzyme that catalyzes the chemical reaction
Hence, this enzyme has one substrate, 2-carboxy-2,5-dihydro-5-oxofuran-2-acetate, and two products, 4,5-dihydro-5-oxofuran-2-acetate and CO2.
This enzyme belongs to the family of lyases, specifically the carboxy-lyases, which cleave carbon-carbon bonds. The systematic name of this enzyme class is 2-carboxy-2,5-dihydro-5-oxofuran-2-acetate carboxy-lyase (4,5-dihydro-5-oxofuran-2-acetate-forming). Other names in common use include gamma-4-carboxymuconolactone decarboxylase, and 4-carboxymuconolactone carboxy-lyase. This enzyme participates in benzoate degradation via hydroxylation.
Structural studies.
As of late 2007, only one structure has been solved for this class of enzymes, with the PDB accession code .