Manipulation of the Precursor Supply in Yeast Significantly Enhances the Accumulation of Prenylated β-Carbolines

Abstract

The tryptophan derivative 1-methyl-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid (MTCA) is present in many plants and foods including fermentation products of the baker's yeast Saccharomyces cerevisiae. MTCA is formed from tryptophan and acetaldehyde via a Pictet-Spengler reaction. In this study, up to 9 mg/L of MTCA were detected as a mixture of (1S,3S) and (1R,3S) isomers in a ratio of 2.2:1 in Saccharomyces cerevisiae cultures. To the best of our knowledge, this is the first report on the presence of MTCA in laboratory baker's yeast cultures. Expression of three fungal tryptophan prenyltransferase genes, fgaPT2, 5-dmats, and 7-dmats in S. cerevisiae resulted in the formation of MTCA derivatives with prenyl moieties at different positions of the indole ring. Expression of these genes in dimethylallyl diphosphate and tryptophan overproducing strains led to generation of up to 400 mg/L of prenylated MTCAs as mixtures of (1S,3S) and (1R,3S) diastereomers in ratios similar to that of unprenylated MTCA. The structures of the described substances including their stereochemistry were unequivocally elucidated by mass spectrometry as well as one- and two-dimensional NMR spectroscopy. The results of this study provide a convenient system for the production of high amounts of designed prenylated MTCAs in S. cerevisiae. Furthermore, our work can be considered as an excellent example for the construction of more complex molecules by introducing just one key gene.

Toward Developing a Yeast Cell Factory for the Production of Prenylated Flavonoids

“…In a recent study, a similar strategy was deployed for enhancing the production of prenylated β-carbolines, which derive from tryptophan. 44 Interestingly, the overproduction of the prenyl donor DMAPP was more effective than overproduction of tryptophan.…”

Engineering metabolic pathways in Amycolatopsis japonicum for the optimization of the precursor supply for heterologous brasilicardin congeners production

“…It is known that in many cases the limiting step in increasing production is the provision of the precursors [e.g. [43] , [44] , [45] ]. The diterpenoid backbone of brasilicardin is synthesized from the five carbon precursor isopentenyl diphosphate (IPP) and its isomer dimethylallyl diphosphate (DMAPP).…”

Plant Aromatic Prenyltransferases: Tools for Microbial Cell Factories

“…Similarly, prenylation of phloroisovalerophenone to form lupulone (hop β-acids; Box 2) in yeast was only successful after chemical downregulation of ergosterol biosynthesis [78]. A likely limitation for a higher product yield in the aforementioned studies was the availability of the prenyl donor DMAPP, as supported by the findings of several other studies on the production of prenylated compounds in yeast [19,[77][78][79].…”