In enzymology, a 1-aminocyclopropane-1-carboxylate deaminase () is an enzyme that catalyzes the chemical reaction 1-aminocyclopropane-1-carboxylate + H2O 2-oxobutanoate + NH3 Thus, the two substrates of this enzyme are 1-aminocyclopropane-1-carboxylate and H2O, whereas its two products are 2-oxobutanoate and NH3. This enzyme belongs to the family of hydrolases, those acting on carbon-nitrogen bonds other than peptide bonds, specifically in compounds that have not been otherwise categorized within EC number 3.5. The systematic name of this enzyme class is 1-aminocyclopropane-1-carboxylate aminohydrolase (isomerizing). This enzyme is also called 1-aminocyclopropane-1-carboxylate endolyase (deaminating). This enzyme participates in propanoate metabolism. It employs one cofactor, pyridoxal phosphate. Structural studies As of late 2007, 6 structures have been solved for this class of enzymes, with PDB accession codes , , , , , and . References EC 3.5.99 Pyridoxal phosphate enzymes Enzymes of known structure