Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, NY, USA.
RNA Biol. 2010 Jan-Feb;7(1):98-103. doi: 10.4161/rna.7.1.10756. Epub 2010 Jan 25.
Riboswitches are gene control elements typically located in the 5' untranslated regions of bacterial mRNAs where they modulate the expression of associated genes in response to elevated concentrations of cellular metabolites. Metabolite binding stabilizes the evolutionarily conserved receptor domains and affects the folding of the downstream gene-controlling modules. About 20 classes of riboswitches display a large number of RNA sequences perfectly adjusted to bind their cognate cellular metabolites. The question of how riboswitches achieve exquisite specificity for various ligands has been answered for almost all major classes of known riboswitches by structural and biochemical studies of their metabolite-sensing domains. Here I outline the most recent additions to the growing collection of riboswitch structures, review the principles of riboswitch folding and metabolite recognition, and discuss whether this information can help us understand the details of genetic control and metabolite recognition in the riboswitches whose three-dimensional structures are not available.
核糖开关是一类基因调控元件，通常位于细菌 mRNA 的 5'非翻译区，它们通过感应细胞内代谢物浓度的变化来调节相关基因的表达。代谢物结合可稳定进化上保守的受体结构域，并影响下游基因调控模块的折叠。约有 20 类核糖开关展示出大量与其天然配体完美适配的 RNA 序列。通过对其代谢物感应结构域的结构和生化研究，几乎所有主要类型的已知核糖开关的配体识别特异性问题都得到了回答。本文概述了日益增多的核糖开关结构研究中的最新进展，综述了核糖开关折叠和代谢物识别的原理，并讨论了这些信息是否有助于我们理解那些三维结构尚未解析的核糖开关的遗传调控和代谢物识别的细节。
