Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, United States.
Howard Hughes Medical Institute, New Haven, United States.
Elife. 2018 Mar 5;7:e33908. doi: 10.7554/eLife.33908.
Gene control systems sometimes interpret multiple signals to set the expression levels of the genes they regulate. In rare instances, ligand-binding riboswitch aptamers form tandem arrangements to approximate the function of specific two-input Boolean logic gates. Here, we report the discovery of riboswitch aptamers for phosphoribosyl pyrophosphate (PRPP) that naturally exist either in singlet arrangements, or occur in tandem with guanine aptamers. Tandem guanine-PRPP aptamers can bind the target ligands, either independently or in combination, to approximate the function expected for an IMPLY Boolean logic gate to regulate transcription of messenger RNAs for de novo purine biosynthesis in bacteria. The existence of sophisticated all-RNA regulatory systems that sense two ancient ribonucleotide derivatives to control synthesis of RNA molecules supports the hypothesis that RNA World organisms could have managed a complex metabolic state without the assistance of protein regulatory factors.
基因控制系统有时会解释多个信号，以设定它们所调节的基因的表达水平。在极少数情况下，配体结合的核酶适体形成串联排列，以近似特定的双输入布尔逻辑门的功能。在这里，我们报告了发现核酶适体对于磷酸核糖焦磷酸（PRPP）的存在，要么是单独存在，要么与鸟嘌呤适体串联存在。串联的鸟嘌呤-PRPP 适体可以独立或组合地结合靶配体，近似于预期的 IMPLY 布尔逻辑门的功能，以调节细菌中新嘌呤生物合成的信使 RNA 的转录。存在复杂的全 RNA 调节系统，可感知两种古老的核苷酸衍生物，以控制 RNA 分子的合成，这支持了这样的假设，即 RNA 世界生物可以在没有蛋白质调节因子帮助的情况下，管理复杂的代谢状态。
