2 H(+) + H2O + urea = CO2 + 2 NH4(+) The apoenzyme can be activated in vitro in the presence of nickel ions and carbon dioxide, which promotes carbamylation of 'Lys-217' of the UreC (alpha) subunit. Optimum pH is 7.75. Nitrogen metabolism; urea degradation; CO(2) and NH(3) from urea (urease route): step 1/1. Heterotrimer of UreA (gamma), UreB (beta) and UreC (alpha) subunits. Three heterotrimers associate to form the active enzyme. The apoenzyme interacts with an accessory complex composed of UreD, UreF and UreG, which is required for the assembly of the nickel containing metallocenter of UreC. The UreE protein may also play a direct role as a metallochaperone in nickel transfer to the urease apoprotein. Belongs to the urease gamma subunit family.