Catalyzes a late step in pyrimidine degradation (, ). Converts N-carbamoyl-beta-alanine (3-ureidopropanoate) into beta-alanine, ammonia and carbon dioxide (  , ). Likewise, converts N-carbamoyl-beta-aminoisobutyrate (3-ureidoisobutyrate) into beta-aminoisobutyrate, ammonia and carbon dioxide (Probable).
Subcellular locations: Cytoplasm
Detected in liver (at protein level).