4 oxalmesaconate hydratase

In enzymology, a 4-oxalmesaconate hydratase (EC 4.2.1.83) is an enzyme that catalyzes the chemical reaction

2-hydroxy-4-oxobutane-1,2,4-tricarboxylate ⇌ (E)-4-oxobut-1-ene-1,2,4-tricarboxylate + H₂O

Hence, this enzyme has one substrate, 2-hydroxy-4-oxobutane-1,2,4-tricarboxylate, and two products, (E)-4-oxobut-1-ene-1,2,4-tricarboxylate and H₂O.

This enzyme belongs to the family of lyases, specifically the hydro-lyases, which cleave carbon-oxygen bonds. The systematic name of this enzyme class is 2-hydroxy-4-oxobutane-1,2,4-tricarboxylate 2,3-hydro-lyase [(E)-4-oxobut-1-ene-1,2,4-tricarboxylate-forming]. Other names in common use include 4-carboxy-2-oxohexenedioate hydratase, 4-carboxy-2-oxobutane-1,2,4-tricarboxylate 2,3-hydro-lyase, oxalmesaconate hydratase, gamma-oxalmesaconate hydratase, 4-carboxy-2-oxohexenedioate hydratase, and 2-hydroxy-4-oxobutane-1,2,4-tricarboxylate 2,3-hydro-lyase. This enzyme participates in benzoate degradation via hydroxylation.