Abstract：
Riboswitch architectures that involve the binding of a single ligand to a single RNA aptamer domain result in ordinary dose-response curves that require approximately a 100-fold change in ligand concentration to cover nearly the full dynamic range for gene regulation. However, by using multiple riboswitches or aptamer domains in tandem, these ligand-sensing structures can produce additional, complex gene control outcomes. In the current study, we have computationally searched for tandem riboswitch architectures in bacteria to provide a more complete understanding of the diverse biological and biochemical functions of gene control elements that are made exclusively of RNA. Numerous different arrangements of tandem homologous riboswitch architectures are exploited by bacteria to create more \'digital\' gene control devices, which operate over a narrower ligand concentration range. Also, two heterologous riboswitch aptamers are sometimes employed to create two-input Boolean logic gates with various types of genetic outputs. These findings illustrate the sophisticated genetic decisions that can be made by using molecular sensors and switches based only on RNA.
摘要：
涉及单个配体与单个RNA适体结构域结合的核糖开关结构导致普通的剂量-反应曲线,其需要配体浓度的大约100倍变化以覆盖几乎全部的基因调节动态范围。然而,通过串联使用多个核糖开关或适体结构域，这些配体传感结构可以产生额外的，复杂的基因控制结果。在目前的研究中,我们通过计算搜索了细菌中的串联核糖开关结构，以更全面地了解完全由RNA组成的基因控制元件的多种生物学和生化功能。细菌利用串联同源核糖开关结构的许多不同排列来创建更多的“数字”基因控制设备，在较窄的配体浓度范围内操作。此外，有时使用两个异源核糖开关适体来创建具有各种类型的遗传输出的双输入布尔逻辑门。这些发现说明了可以通过使用仅基于RNA的分子传感器和开关来做出复杂的遗传决定。
