This model describes N-acetylglutamate kinases (ArgB) of many prokaryotes and the N-acetylglutamate kinase domains of multifunctional proteins from yeasts. This enzyme is the second step in the "acetylated" ornithine biosynthesis pathway. A related group of enzymes representing the first step of the pathway contain a homologous domain and are excluded from this model. [Amino acid biosynthesis, Glutamate family]