Optimization of PSIV IRES-based eukaryotic kt-ON-riboswitches responsive to theophylline. (A) Predicted partial secondary structures of rationally designed eukaryotic kt-ON-riboswitches with the split theophylline aptamer (theo-ISL). (B) Relative fluorescence intensities of YPet expressed from DNA templates encoding theo-ISL before the YPet gene (T7-theo-ISL-Y) in the absence or presence of 1 mM theophylline (theo) in the WGE-cIVTT system. (C) Relative fluorescence intensities of YPet expressed by conventional translation of mRNA with theo-IS14 (theo-IS14-Y) in the absence or presence of 1 mM theophylline in WGE. (D) Relative amounts of mRNA transcribed from the DNA template encoding theo-IS14 (T7-theo-IS14-Y) in the absence or presence of 1 mM theophylline under the cIVTT conditions. The error bars represent the standard deviation (n = 4).
