Biology

Metabolic pathway

Gene expression

Squalene

Gene

Transcriptome

Biochemistry

Genome

Proceedings of the National Academy of Sciences

The consumption of sweeteners, natural as well as synthetic sugars, is implicated in an array of modern-day health problems. Therefore, natural nonsugar sweeteners are of increasing interest. We identify here the biosynthetic pathway of the sweet triterpenoid glycoside mogroside V, which has a sweetening strength of 250 times that of sucrose and is derived from mature fruit of luo-han-guo (Siraitia grosvenorii, monk fruit). A whole-genome sequencing of Siraitia, leading to a preliminary draft of the genome, was combined with an extensive transcriptomic analysis of developing fruit. A functional expression survey of nearly 200 candidate genes identified the members of the five enzyme families responsible for the synthesis of mogroside V: squalene epoxidases, triterpenoid synthases, epoxide hydrolases, cytochrome P450s, and UDP-glucosyltransferases. Protein modeling and docking studies corroborated the experimentally proven functional enzyme activities and indicated the order of the metabolic steps in the pathw...

The biosynthetic pathway of the nonsugar, high-intensity sweetener mogroside V from <i>Siraitia grosvenorii</i>

The biosynthetic pathway of the nonsugar, high-intensity sweetener mogroside V from Siraitia grosvenorii