RNA Switches for Synthetic Biology

In addition to coding for protein sequences, RNA molecules encode a diverse set of generegulatory elements. RNA switches are one class of gene-regulatory elements that control protein expression in a manner that is dependent on the concentration of specific ligand molecules. These allosteric gene-regulatory elements have been shown as useful tools in engineering diverse cell types to display novel function. In particular, RNA switches have been used as genetically encoded biosensors and conditional controllers to direct cellular decisions based on the system's changing environment. A significant focus in the field has been the generation of novel RNA switches that are tailored for different biological systems. We review approaches that have been used to generate RNA switches, which leverage the unique physical properties of RNA and the myriad ways in which RNA can modulate gene expression. Outline 1 Naturally occurring riboswitches can serve as a starting point for designing engineered RNA switches 2 RNA switches can be rationally designed using rules-based approaches 3 Computational tools enable a more efficient RNA switch design process 4 High-throughput screening of RNA switch libraries allows for generation of highly functional switch sequences 5 Conclusions