Identification of oxidosqualene cyclases associated with saponin biosynthesis from Astragalus membranaceus reveals a conserved motif important for catalytic function.

ABSTRACT:

Introduction

Triterpenoids and saponins have a broad range of pharmacological activities. Unlike most legumes which contain mainly oleanane-type scaffold, Astragalus membranaceus contains not only oleanane-type but also cycloartane-type saponins, for which the biosynthetic pathways are unknown.

Objectives

This work aims to study the function and catalytic mechanism of oxidosqualene cyclases (OSCs), one of the most important enzymes in triterpenoid biosynthesis, in A. membranaceus.

Methods

Two OSC genes, AmOSC2 and AmOSC3, were cloned from A. membranaceus. Their functions were studied by heterologous expression in tobacco and yeast, together with in vivo transient expression and virus-induced gene silencing. Site-directed mutagenesis and molecular docking were used to

SUBMITTER: Chen K 

PROVIDER: S-EPMC9811366 | biostudies-literature | 2023 Jan

REPOSITORIES: biostudies-literature