The enzyme <small>D</small>-dopachrome decarboxylase () catalyzes the chemical reaction
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 D-dopachrome carboxy-lyase (5,6-dihydroxyindole-forming). Other names in common use include phenylpyruvate tautomerase II, D-tautomerase, D-dopachrome tautomerase, and D-dopachrome carboxy-lyase.