AAK_NAGS-Urea: N-acetylglutamate (NAG) kinase-like domain of the NAG Synthase (NAGS) of the urea cycle found in animals. Ureogenic NAGS is a mitochondrial enzyme catalyzing the formation of NAG from acetylcoenzyme A and L-glutamate; NAG is an essential allosteric activator of carbamylphosphate synthase I, the first and rate limiting enzyme of the urea cycle. Ureogenic NAGS activity is dependent on the concentration of glutamate (substrate) and arginine (activator). Domain architecture of ureogenic NAGS consists of an N-terminal NAG kinase-like (ArgB) domain (this CD) and a C-terminal DUF619 domain. Members of this CD belong to the protein superfamily, the Amino Acid Kinase Family (AAKF).