In enzymology, a urea carboxylase (EC 6.3.4.6) is an enzyme that catalyzes the chemical reaction

ATP + urea + HCO₃- ${\displaystyle \rightleftharpoons }$ ADP + phosphate + urea-1-carboxylate

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.

• Allophanate hydrolase

• Roon RJ; Levenberg B (1970). "[37a] ATP: Urea amidolyase (ADP) (Candida utilis)". Metabolism of Amino Acids and Amines Part A. Methods in Enzymology. Vol. 17A. pp. 317–324. doi:10.1016/0076-6879(71)17204-7. ISBN 9780121818746.
• Roon RJ, Levenberg B (1972). "Urea amidolyase. I. Properties of the enzyme from Candida utilis". J. Biol. Chem. 247 (13): 4107–13. doi:10.1016/S0021-9258(19)45046-1. PMID 4556303.
• Sumrada RA, Cooper TG (1982). "Urea carboxylase and allophanate hydrolase are components of a multifunctional protein in yeast". J. Biol. Chem. 257 (15): 9119–27. doi:10.1016/S0021-9258(18)34251-0. PMID 6124544.
• Kanamori T, Kanou N, Atomi H, Imanaka T (2004). "Enzymatic characterization of a prokaryotic urea carboxylase". J. Bacteriol. 186 (9): 2532–9. doi:10.1128/JB.186.9.2532-2539.2004. PMC 387783. PMID 15090492.