Tissue Especificity: Mainly in liver and intestinal mucosa

The plant enzyme also catalyses the reactions of EC 2.1.3.6 (putrescine carbamoyltransferase), EC 2.7.2.2 (carbamate kinase) and EC 3.5.3.12 (agmatine deiminase), thus acting as putrescine synthase, converting agmatine and ornithine into putrescine and citrulline, respectively.

Ornithine carbamoyltransferase catalyzes the conversion of ornithine and carbamoyl phosphate to citrulline. In mammals this enzyme participates in the urea cycle and is located in the mitochondrial matrix. In prokaryotes and eukaryotic microorganisms it is involved in the biosynthesis of arginine. In some bacterial species it is also involved in the degradation of arginine (the arginine deaminase pathway).

It has been shown that OTC is evolutionary related to aspartate carbamoyltransferase (EC 2.1.3.2). The predicted secondary structure of both enzymes are similar and there are some regions of sequence similarities. One of these regions includes three
residues which have been shown, by crystallographic studies , to be implicated in binding the phosphoryl group of carbamoyl phosphate. This region has been selected as a signature for these enzymes.