[2] The protein itself is composed of 676 amino acids which then fold, producing the final product which has 2 identical subunits, making the enzyme a homodimer.

To catalyze the hydrolysis of urocanate in the catabolic pathway of L-histidine the enzyme utilizes its two NAD+ (Nicotinamide Adnene Dinucleotide) groups.

[3] This rearrangement allows for the addition of a water molecule, converting the urocanate into 4,5-dihydro-4-oxo-5-imidazolepropanoate.

Urocanase is a protein of about 60 Kd, it binds tightly to NAD+ and uses it as an electrophil cofactor.

A conserved cysteine has been found to be important for the catalytic mechanism and could be involved in the binding of the NAD+.