Zheng Luqian, Song Qianqian, Xu Xiaochen, Shen Xin, Li Chunyan, Li Hongcheng, Chen Hao, Ren Aiming
Department of Gastroenterology, Department of Cardiology of the Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310058, China.
Life Sciences Institute, Zhejiang University, Hangzhou, 310058, China.
Sci China Life Sci. 2023 Jan;66(1):31-50. doi: 10.1007/s11427-022-2188-7. Epub 2022 Nov 29.
Riboswitches are highly conserved RNA elements that located in the 5'-UTR of mRNAs, which undergo real-time structure conformational change to achieve the regulation of downstream gene expression by sensing their cognate ligands. S-adenosylmethionine (SAM) is a ubiquitous methyl donor for transmethylation reactions in all living organisms. SAM riboswitch is one of the most abundant riboswitches that bind to SAM with high affinity and selectivity, serving as regulatory modules in multiple metabolic pathways. To date, seven SAM-specific riboswitch classes that belong to four families, one SAM/SAH riboswitch and one SAH riboswitch have been identified. Each SAM riboswitch family has a well-organized tertiary core scaffold to support their unique ligand-specific binding pocket. In this review, we summarize the current research progress on the distribution, structure, ligand recognition and gene regulation mechanism of these SAM-related riboswitch families, and further discuss their evolutionary prospects and potential applications.
核糖开关是高度保守的RNA元件，位于mRNA的5'-非翻译区，通过感知其同源配体进行实时结构构象变化，以实现对下游基因表达的调控。S-腺苷甲硫氨酸（SAM）是所有生物体中普遍存在的甲基化反应甲基供体。SAM核糖开关是最丰富的核糖开关之一，能以高亲和力和选择性结合SAM，在多种代谢途径中作为调控模块。迄今为止，已鉴定出属于四个家族的七类SAM特异性核糖开关、一类SAM/SAH核糖开关和一类SAH核糖开关。每个SAM核糖开关家族都有一个组织良好的三级核心支架，以支持其独特的配体特异性结合口袋。在本综述中，我们总结了这些与SAM相关的核糖开关家族在分布、结构、配体识别和基因调控机制方面的当前研究进展，并进一步讨论了它们的进化前景和潜在应用。
