Institute for Organic Chemistry and Chemical Biology, Johann Wolfgang Goethe University, Max-von-Laue-Str. 7, 60438, Frankfurt/Main, Germany.
Center for Biomolecular Magnetic Resonance, Institute for Organic Chemistry and Chemical Biology, Johann Wolfgang Goethe University, Max-von-Laue-Str. 7-9, 60438, Frankfurt/Main, Germany.
Chembiochem. 2022 Feb 4;23(3):e202100564. doi: 10.1002/cbic.202100564. Epub 2021 Dec 9.
Riboswitches are regulatory RNA elements that undergo functionally important allosteric conformational switching upon binding of specific ligands. The here investigated guanidine-II riboswitch binds the small cation, guanidinium, and forms a kissing loop-loop interaction between its P1 and P2 hairpins. We investigated the structural changes to support previous studies regarding the binding mechanism. Using NMR spectroscopy, we confirmed the structure as observed in crystal structures and we characterized the kissing loop interaction upon addition of Mg and ligand for the riboswitch aptamer from Escherichia coli. We further investigated closely related mutant constructs providing further insight into functional differences between the two (different) hairpins P1 and P2. Formation of intermolecular interactions were probed by small-angle X-ray scattering (SAXS) and NMR DOSY data. All data are consistent and show the formation of oligomeric states of the riboswitch induced by Mg and ligand binding.
Riboswitches 是调节 RNA 元件，在结合特定配体时会发生功能重要的变构构象切换。这里研究的胍-II 核糖开关结合小阳离子胍，并在其 P1 和 P2 发夹之间形成亲吻环-环相互作用。我们研究了结构变化，以支持先前关于结合机制的研究。使用 NMR 光谱学，我们证实了与晶体结构中观察到的结构一致，并在添加 Mg 和配体后对来自大肠杆菌的核糖开关适体的亲吻环相互作用进行了表征。我们进一步研究了密切相关的突变体构建体，为两个（不同的）发夹 P1 和 P2 之间的功能差异提供了更深入的了解。通过小角 X 射线散射 (SAXS) 和 NMR DOSY 数据探测分子间相互作用的形成。所有数据都是一致的，显示出由 Mg 和配体结合诱导的核糖开关寡聚状态的形成。
