Tryptophan 5-monooxygenase

In enzymology, a tryptophan 5-monooxygenase is an enzyme that catalyzes the chemical reaction


 * L-tryptophan + tetrahydrobiopterin + O2 $$\rightleftharpoons$$ 5-hydroxy-L-tryptophan + 4a-hydroxytetrahydrobiopterin

The 3 substrates of this enzyme are L-tryptophan, tetrahydrobiopterin, and O2, whereas its two products are 5-hydroxy-L-tryptophan and 4a-hydroxytetrahydrobiopterin.

This enzyme belongs to the family of oxidoreductases, specifically those acting on paired donors, with O2 as oxidant and incorporation or reduction of oxygen. The oxygen incorporated need not be derived from O2 with reduced pteridine as one donor, and incorporation of one ato of oxygen into the other donor. The systematic name of this enzyme class is L-tryptophan,tetrahydrobiopterin:oxygen oxidoreductase (5-hydroxylating). Other names in common use include L-tryptophan hydroxylase, indoleacetic acid-5-hydroxylase, tryptophan 5-hydroxylase, and tryptophan hydroxylase. This enzyme participates in tryptophan metabolism. It employs one cofactor, iron.

Structural studies
As of late 2007, only one structure has been solved for this class of enzymes, with the PDB accession code.