Regulation of the carbamoylphosphate synthetase belonging to the arginine biosynthetic pathway of Saccharomyces cerevisiae

Two classes of regulatory mutations affecting the synthesis of the carbamoylphosphate synthetase belonging to the arginine biosynthetic pathway have been selected in Saccharomyces cerevisiae. Together, they delineate a negative type of control. The cpaI0 mutations, closely linked with one of the two genes coding for the enzyme and cis dominant, meet properties of operator mutations. The cpaR mutations can be interpreted as mutations impairing the formation of an active repressor of carbamoylphosphate synthetase which is distinct from the one acting on the synthesis of the other enzymes of the arginine biosynthetic pathway.