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Updated: Nov 5, 2025

Functional Characterization of RING-Type E3 Ubiquitin Ligases In Vitro and In Planta
Published on: December 5, 2019
Site-directed mutagenesis and substrate compatibility to reveal the structure-function relationships of plant
Kuan Chen1, Meng Zhang1, Min Ye1
1State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Beijing 100191, China. yemin@bjmu.edu.cn.
Abstract:
Covering: up to May 2020Oxidosqualene cyclases (OSCs) catalyze one of the most complex polycyclization reactions in nature, using the linear 2,3-oxidosqualene to generate an array of triterpene skeletons in plants. Despite the structural diversity of the products, the protein sequences of plant OSCs are highly conserved, where a few key amino acids could govern the product selectivity. Due to the absence of crystal structures, site-directed mutagenesis and substrate structural modification become key approaches to understand the cyclization mechanism. In this review, 98 mutation sites in 25 plant OSCs have been summarized, and the conserved key residues have been identified by sequence alignment. Structure-function relationships are further discussed. Meanwhile, the substrate selectivity has been summarized to probe the active site cavity of plant OSCs. A total of 77 references are included.
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