Oxidative reactions catalyzed by IDO. (A) C-4 hydroxylation of l-Ile into (2S,3R,4S)-HIL and further dehydrogenation of (2S,3R,4S)-HIL into (2S,3R)-AMKP. (B) C-4 hydroxylation of l-norvaline, l-leucine, and l-norleucine, as well as l-Ile. (C) C-5 hydroxylation of l-norleucine. (D) C-3 hydroxylation of l-allo-Ile. (E) Sulfoxidation of l-methionine and l-ethionine.