Life Sciences Institute, Second Affiliated Hospital of Zhejiang University School of Medicine, Zhejiang Key Laboratory of Biotherapy, Zhejiang University, Hangzhou 310058, China.
The Eighth Affiliated Hospital, Sun Yat-sen University, Shenzhen 518033, China.
Nucleic Acids Res. 2024 Aug 12;52(14):8454-8465. doi: 10.1093/nar/gkae377.
Riboswitches are conserved regulatory RNA elements participating in various metabolic pathways. Recently, a novel RNA motif known as the folE RNA motif was discovered upstream of folE genes. It specifically senses tetrahydrofolate (THF) and is therefore termed THF-II riboswitch. To unravel the ligand recognition mechanism of this newly discovered riboswitch and decipher the underlying principles governing its tertiary folding, we determined both the free-form and bound-form THF-II riboswitch in the wild-type sequences. Combining structural information and isothermal titration calorimetry (ITC) binding assays on structure-based mutants, we successfully elucidated the significant long-range interactions governing the function of THF-II riboswitch and identified additional compounds, including alternative natural metabolites and potential lead compounds for drug discovery, that interact with THF-II riboswitch. Our structural research on the ligand recognition mechanism of the THF-II riboswitch not only paves the way for identification of compounds targeting riboswitches, but also facilitates the exploration of THF analogs in diverse biological contexts or for therapeutic applications.
Riboswitches 是保守的调控 RNA 元件，参与各种代谢途径。最近，在 folE 基因的上游发现了一种新的 RNA 基序，称为 folE RNA 基序。它特异性地感知四氢叶酸 (THF)，因此被称为 THF-II 核糖开关。为了揭示这种新发现的核糖开关的配体识别机制，并阐明其三级折叠的基本原理，我们确定了野生型序列中游离形式和结合形式的 THF-II 核糖开关。结合结构信息和基于结构的突变体等温滴定量热 (ITC) 结合测定，我们成功阐明了控制 THF-II 核糖开关功能的重要远程相互作用，并鉴定了其他化合物，包括替代天然代谢物和用于药物发现的潜在先导化合物，它们与 THF-II 核糖开关相互作用。我们对 THF-II 核糖开关配体识别机制的结构研究不仅为鉴定针对核糖开关的化合物铺平了道路，还促进了在不同生物背景下或用于治疗应用的 THF 类似物的探索。
