In enzymology, 2-hydroxymuconate-semialdehyde hydrolase () is an enzyme that catalyzes the chemical reaction
The two substrates of this enzyme are 2-hydroxymuconate semialdehyde and water. Its products are 2-oxopent-4-enoic acid and formic acid.
This enzyme belongs to the family of hydrolases, specifically those acting on carbon-carbon bonds in ketonic substances. The systematic name of this enzyme class is 2-hydroxymuconate-semialdehyde formylhydrolase. Other names in common use include 2-hydroxy-6-oxohepta-2,4-dienoate hydrolase, 2-hydroxymuconic semialdehyde hydrolase, HMSH, and HOD hydrolase. This enzyme participates in 5 metabolic pathways: benzoate degradation via hydroxylation, toluene and xylene degradation, 1,4-dichlorobenzene degradation, carbazole degradation, and styrene degradation.
As of late 2007, 10 structures have been solved for this class of enzymes, with PDB accession codes , , , , , , , , , and .