In enzymology, an aminoimidazolase (EC 3.5.4.8) is an enzyme that catalyzes the chemical reaction 4-aminoimidazole + H2O unidentified product + NH3 Thus, the two substrates of this enzyme are and H2O, whereas its two products are and NH3. This enzyme belongs to the family of hydrolases, those acting on carbon-nitrogen bonds other than peptide bonds, specifically in cyclic amidines. The systematic name of this enzyme class is 4-aminoimidazole aminohydrolase. This enzyme is also called 4-aminoimidazole hydrolase. This enzyme participates in purine metabolism. It employs one cofactor, iron.