5-hydroxytryptophan (5-HTP) as a drug has been clinically used for 30 years. 5-HTP for depression, insomnia, fibromyalgia, obesity, cerebellar movement disorders and chronic headache have a good therapeutic effect. It is difficult to selectively form 5-HTP by selective hydroxylation of tryptophan by chemical reaction. The commercial production of 5-HTP is now extracted from African Ghana seeds. The regional and seasonal supply of raw materials limits its low-cost production and widespread clinical use. The use of genetically engineered strains to produce 5-HTP by fermentation has a high application value. In humans and other animals, 5-HTP is converted to tryptophan by tryptophan hydroxylase (T5H). however, animal-derived T5H is unstable and it is difficult to express high activity in microbes.

the project was designed to construct a new 5-HTP biosynthetic pathway. First, the precursor 5-hydroxyanthranilic acid (5-HAA) can be converted to 1.2 g / L 5-HTP by expressing the relevant enzyme of Escherichia coli itself in the tryptophan synthesis pathway. Then, 5-hydroxyanthranilic acid (5-HAA) was produced by the production of anthranilic acid from the metabolite of Escherichia coli by introducing anthranilic acid 5-hydroxylase. Finally, 5-HTP was produced from glucose by metabolizing the shikimic acid pathway. this approach avoids the use of unstable T5H and its cofactor regeneration system, providing a new approach for the production of 5-HTP by fermentation.