Urocanase

Urocanase (also known as imidazolonepropionate hydrolase or urocanate hydratase) is the enzyme that catalyzes the second step in the degradation of histidine, the hydration of urocanate into imidazolonepropionate.

Inherited deficiency of urocanase leads to elevated levels of urocanic acid in the urine, a condition known as urocanic aciduria.