Reaction: L-tryptophan + tetrahydrobiopterin + O2 = 5-hydroxy-L-tryptophan + 4a-hydroxytetrahydrobiopterin
For diagram click here.
Other name(s): L-tryptophan hydroxylase; indoleacetic acid-5-hydroxylase; tryptophan 5-hydroxylase; tryptophan hydroxylase
Systematic name: L-tryptophan,tetrahydrobiopterin:oxygen oxidoreductase (5-hydroxylating)
Comments: The active centre contains mononuclear iron(II). The enzyme is activated by phosphorylation, catalysed by a Ca2+-activated protein kinase. The 4a-hydroxytetrahydrobiopterin formed can dehydrate to 6,7-dihydrobiopterin, both spontaneously and by the action of EC 18.104.22.168, 4a-hydroxytetrahydrobiopterin dehydratase. The 6,7-dihydrobiopterin can be enzymically reduced back to tetrahydrobiopterin, by EC 22.214.171.124 (6,7-dihydropteridine reductase), or slowly rearranges into the more stable compound 7,8-dihydrobiopterin.
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 9037-21-2
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