In enzymology, a urea carboxylase is an enzyme that catalyzes the chemical reaction The 3 substrates of this enzyme are ATP, urea, and HCO3-, whereas its 3 products are ADP, phosphate, and urea-1-carboxylate (allophanate). This enzyme belongs to the family of ligases, specifically those forming generic carbon-nitrogen bonds. The systematic name of this enzyme class is urea:carbon-dioxide ligase (ADP-forming). This enzyme participates in urea cycle and metabolism of amino groups. It employs one cofactor, biotin.