<p>Imidazolonepropionase catalyzes the third step in histidine degradation. It hydrolyses the carbon-nitrogen bonds in 4-imidazolone-5-propionic acid to yield N-formimino-l-glutamic acid [<cite idref="PUB00043335"/>]. The enzyme contains two domains, a TIM (triose-phosphate isomerase) barrel domain with two insertions and a small beta-sandwich domain. It has been conserved from bacteria to eukaryotes [<cite idref="PUB00043336"/>].</p> Imidazolonepropionase