2 hydroxy 4 carboxymuconate semialdehyde hemiacetal dehydrogenase

2-hydroxy-4-carboxymuconate semialdehyde hemiacetal dehydrogenase (EC 1.1.1.312, 2-hydroxy-4-carboxymuconate 6-semialdehyde dehydrogenase, 4-carboxy-2-hydroxy-cis,cis-muconate-6-semialdehyde:NADP⁺ oxidoreductase, alpha-hydroxy-gamma-carboxymuconic epsilon-semialdehyde dehydrogenase, 4-carboxy-2-hydroxymuconate-6-semialdehyde dehydrogenase, LigC, ProD) is an enzyme with systematic name 4-carboxy-2-hydroxymuconate semialdehyde hemiacetal:NADP⁺ 2-oxidoreductase. This enzyme catalyses the following chemical reaction

4-carboxy-2-hydroxymuconate semialdehyde hemiacetal + NADP⁺ ⇌ 2-oxo-2H-pyran-4,6-dicarboxylate + NADPH + H⁺

Unsubstituted aliphatic or aromatic aldehydes or glucose cannot serve as substrate of this enzyme.