label: (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tryptophan + O2 <=> 5-hydroxy-L-tryptophan + (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin
label_lc: (6r)-l-erythro-5,6,7,8-tetrahydrobiopterin + l-tryptophan + o2 <=> 5-hydroxy-l-tryptophan + (4as,6r)-4a-hydroxy-l-erythro-5,6,7,8-tetrahydrobiopterin