State Key Laboratory of Microbial Metabolism, School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai, China.
National Facility for Protein Science (Shanghai), Zhangjiang Lab, Shanghai Advanced Research Institute, Chinese Academy of Science, Shanghai, China.
RNA Biol. 2021 Nov;18(11):2007-2015. doi: 10.1080/15476286.2021.1886755. Epub 2021 Feb 25.
Ligand binding and temperature play important roles in riboswitch RNAs' structures and functions. However, most studies focused on studying structural dynamics or gene-regulation function of riboswitches from the aspect of ligand, instead of temperature. Here we combined NMR, ITC, stopped-flow and assays to investigate the ligand-triggered switch of adenine riboswitch from 10 to 45°C. Our results demonstrated that at single-nucleotide resolution, structural regions sensed ligand and temperature diversely. Temperature had opposite effects on ligand-binding and gene-regulation of adenine riboswitch. Compared with higher temperature, the RNA bound with its cognate ligand obviously stronger, while its regulatory capacity was weakened at lower temperature. In addition, application of specific-labelled RNAs to the stopped-flow experiments identified the real-time folding of the specific positions upon ligand addition at different temperatures. The kissing loop and internal loop at the riboswitch responded to ligand and temperature differently. The distinct thermo-dynamics of adenine riboswitch exposed here may contribute to the fields of RNA sensors and drug design.
配体结合和温度在核糖开关 RNA 的结构和功能中起着重要作用。然而,大多数研究都从配体的角度研究核糖开关的结构动力学或基因调控功能,而不是温度。在这里,我们结合 NMR、ITC、停流和荧光各向异性实验,在 10 到 45°C 的温度范围内研究了腺嘌呤核糖开关的配体触发开关。我们的结果表明,在单核苷酸分辨率下,结构区域以不同的方式感知配体和温度。温度对腺嘌呤核糖开关的配体结合和基因调控有相反的影响。与较高温度相比,RNA 与其同源配体的结合明显更强,而在较低温度下其调节能力减弱。此外,将特定标记的 RNA 应用于停流实验,在不同温度下,在配体加入时,能够识别特定位置的实时折叠。核糖开关的发夹环和内环对配体和温度的反应不同。这里揭示的腺嘌呤核糖开关的独特热力学性质可能有助于 RNA 传感器和药物设计领域。