Characterization of a 4'-O-rhamnosyltransferase and de novo biosynthesis of bioactive steroidal triglycosides from Paris polyphylla.

ABSTRACT: Steroidal saponins in Paris polyphylla featuring complicated sugar chains exhibit notable biological activities, but their sugar-chain biosynthesis is still not fully understood. Here, we identified a 4'-O-rhamnosyltransferase (UGT73DY2) from P. polyphylla, which catalyzes the 4'-O-rhamnosylation of polyphyllins V and VI, producing dioscin and pennogenin 3-O-β-chacotrioside, respectively. UGT73DY2 exhibits strict substrate specificity toward steroidal diglycosides and UDP-rhamnose, and a new steroidal triglycoside can be synthesized through enzyme catalysis. A mutation library was generated based on semi-rational design, identifying three mutants, I358T, A342V, and A132T, which displayed approximately two-fold enhanced enzyme activity. Molecular dynamics simulations revealed that shortened

SUBMITTER: Zhao CX 

PROVIDER: S-EPMC12010398 | biostudies-literature | 2025 Apr

REPOSITORIES: biostudies-literature