Hydrolyzes ureidoacrylate to form aminoacrylate and carbamate. The carbamate hydrolyzes spontaneously, thereby releasing one of the nitrogen atoms of the pyrimidine ring as ammonia and one of its carbon atoms as CO2. (Z)-3-ureidoacrylate + H(+) + H2O = (Z)-3-aminoacrylate + CO2 + NH4(+) (Z)-3-ureidoacrylate + H2O = (Z)-3-aminoacrylate + carbamate + H(+) (Z)-2-methylureidoacrylate + H(+) + H2O = (Z)-2-methylaminoacrylate + CO2 + NH4(+) Up-regulated by the nitrogen regulatory protein C (NtrC also called GlnG) and repressed by RutR. Cells lacking this gene fail to grow on uridine as the sole source of nitrogen at room temperature. The Rut pathway degrades exogenous pyrimidines as the sole nitrogen source at room temperature but not at 37 degrees Celsius, a restriction that is apparently a consequence of an inadequate ability to remove toxic malonic semialdehyde at the higher temperature (RutE/YdfG function). Belongs to the isochorismatase family. RutB subfamily.