Putative carbamoyltransferase. No activity can be detected with allantoin or 25 other related compounds, including 20 naturally occurring amino acids, N-acetyl-L-ornithine, N-succinyl-L-ornithine, L-ornithine, oxamate, beta-alanine and putrescine. Homotrimer. Contains a carbamoyl phosphate domain (CPD) and a second substrate domain (SSD), which are linked by two helices. Belongs to the aspartate/ornithine carbamoyltransferase superfamily.