- DNA sequence of the carA gene and the control region of carAB: tandem promoters, respectively controlled by arginine and the pyrimidines, regulate the synthesis of carbamoyl-phosphate synthetase in Escherichia coli K-12. Piette, J., Nyunoya, H., Lusty, C.J., Cunin, R., Weyens, G., Crabeel, M., Charlier, D., Glansdorff, N., Piérard, A. Proc. Natl. Acad. Sci. U.S.A. (1984)