In enzymology, an ATP deaminase () is an enzyme that catalyzes the chemical reaction ATP + H2O ITP + NH3 Thus, the two substrates of this enzyme are ATP and H2O, whereas its two products are ITP 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 ATP aminohydrolase. This enzyme is also called adenosine triphosphate deaminase. References EC 3.5.4 Enzymes of unknown structure