acetyl-CoA + L-glutamate = CoA + H(+) + N-acetyl-L-glutamate Feedback inhibition by L-arginine. Amino-acid biosynthesis; L-arginine biosynthesis; N(2)-acetyl-L-ornithine from L-glutamate: step 1/4. Homohexamer. The mutant strains shown below are all feedback-resistant (fbr) strains exhibiting enhanced arginine biosynthesis. Belongs to the acetyltransferase family. ArgA subfamily.