2.3.1.1 malfunction enzyme deficiency results in elevated levels of plasma ammonia which is neurotoxic 737116 2.3.1.1 metabolism Sulfolobus solfataricus lacks ornithine acetyltransferase and thus forms N-acetylglutamate exclusively via the energetically less favourable reaction catalysed by N-acetylglutamate synthase, investing 1 mol of acetyl CoA per mol of N-acetyl intermediate synthesized -, 725629 2.3.1.1 physiological function first enzyme of bacterial and plant arginine biosynthesis, activator of urea cycle in animals 703696, 703712 2.3.1.1 physiological function first step in L-arginine biosynthesis in plants and micro organsims, inactive T-state with L-arginine bound and active R-state complexed with CoA and L-glutamate 704614 2.3.1.1 physiological function N-acetylglutamate synthase catalyzes the synthesis of N-acetyl-L-glutamate, an obligate cofactor for carbamyl phosphate synthetase I in the urea cycle. An N-terminal proline-rich motif of the enzyme is likely to function in signal transduction to carbamyl phosphate synthetase I, CPS1 737116 2.3.1.1 physiological function the enzyme plays a role in citrulline and/or arginine biosynthesis during the first day of development and in ammonia detoxification thereafter 737139