N acetylglutamate serve as allosteric actor of which of the following enzyme in the urea cycle?

N acetylglutamate serve as allosteric actor of Carbamoyl phosphate synthetase I, by enhancing the affinity of the synthase for ATP. N acetyl glutamate is synthesized from acetyl CoA and glutamate in a reaction for which arginine is an activator. Some reactions of urea cycle occur in the mitochondria and some occur in the cytoplasm. Synthesis of 1 mol of urea requires 3 mol of ATP, 1 mol each of ammonium ion and of aspaate, and employs five enzymes. Carbamoyl phosphate synthetase I which catalyse the condensation of CO2, ammonia, and ATP to form carbamoyl phosphate is the rate limiting enzyme in urea synthesis. Ref: Biochemistry By Pamela C. Champe, page 253.