Reverse prenylation in plants by non-canonical aromatic prenyltransferases

Area of Science:

• Plant biochemistry
• Natural product biosynthesis
• Enzymology

Background:

• Reverse-prenylated phenolic compounds are important bioactive natural products.
• Hyperixanthone A, a reverse-prenylated xanthone, inhibits multidrug-resistant Staphylococcus aureus.
• Enzymes for forward prenylation are known, but reverse prenylation enzymes in plants were undiscovered.

Purpose of the Study:

• Identify and characterize plant enzymes responsible for reverse prenylation of aromatic compounds.
• Elucidate the mechanism of reverse prenylation by these novel enzymes.
• Explore the biotechnological potential of these enzymes for natural product modification.

Main Methods:

• Metabolic profiling and transcriptomics in Hypericum species.
• In vitro, in vivo, and in silico functional characterization of candidate enzymes.
• Enzyme cascade reconstruction in Saccharomyces cerevisiae and Nicotiana benthamiana.
• Molecular modeling, docking simulations, and site-directed mutagenesis.

Main Results:

• Identified non-canonical UbiA-type prenyltransferases catalyzing both forward and reverse prenylations.
• Demonstrated these enzymes produce reverse-prenylated Hyperixanthone A in engineered yeast and plants.
• Elucidated distinct binding modes enabling dual prenylation regioselectivity via structural studies.

Conclusions:

• Discovered plant enzymes capable of catalyzing reverse prenylation of aromatic carbons.
• Expanded the known functions of membrane-bound UbiA-type plant aromatic prenyltransferases.
• Provided novel enzymes for potential biotechnological production of valuable natural products.