2 Hydroxymuconate 6 semialdehyde dehydrogenase

2-Hydroxymuconate-6-semialdehyde dehydrogenase (EC 1.2.1.85, xylG (gene), praB (gene)) is an enzyme with systematic name (2E,4Z)-2-hydroxy-6-oxohexa-2,4-dienoate:NAD⁺ oxidoreductase. This enzyme catalyses the following chemical reaction

2-hydroxymuconate-6-semialdehyde + NAD⁺ + H₂O ⇌ (2Z,4E)-2-hydroxyhexa-2,4-dienedioate + NADH + 2 H⁺

This substrate for this enzyme is formed by meta ring cleavage of catechol (EC 1.13.11.2, catechol 2,3-dioxygenase), and is an intermediate in the bacterial degradation of several aromatic compounds.