Involved in the arginine biosynthetic pathway via the intermediate compound ornithine. ATP + N-acetyl-L-glutamate = ADP + N-acetyl-L-glutamyl 5-phosphate Inhibited by arginine. Inhibition is relieved by binding to GLB1. Amino-acid biosynthesis; L-arginine biosynthesis; N(2)-acetyl-L-ornithine from L-glutamate: step 2/4. Interacts with GLB1. Interaction is dependent of MgATP and inhibited by 2-oxoglutarate, arginine, glutamate, citrate, and oxaloacetate. Belongs to the acetylglutamate kinase family. ArgB subfamily.