2-Hydroxymuconate-6-semialdehyde dehydrogenase (, [gene], [gene] ) is an enzyme with systematic name (2E,4Z)-2-hydroxy-6-oxohexa-2,4-dienoate:NAD<sup>+</sup> oxidoreductase. This enzyme catalyses the following chemical reaction
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.