Fig. 2: Recognition and binding of uncharged and charged tRNAs by core ileS T-box riboswitch.
a Electrophoretic mobility shift assay (EMSA) showing the binding between different tRNA constructs and core region of T-box riboswitch (T166). The results were consistent across all three independent experimental replicates. b Dimensionless Kratky plots for T166 in complex with different tRNA constructs. c Schematic representation of the different fluorescent labeling constructs of T-box-tRNA complexes for smFRET analysis. The green and blue circles represent the Cy3 and Cy5 fluorophores, respectively. d Representative smFRET traces (left), FRET histograms (middle) and transition density plots (right) for the respective labeling constructs in c in the presence of 20 mM Mg2+ and three different tRNA constructs: tRNAΔ, tRNAIle and tRNA78. Green, blue and black lines represent the Cy3 intensity, Cy5 intensity and FRET efficiency, respectively. FRET histograms were well fitted with Guassion peaks, shown in red and blue for the low- and middle- or high-FRET, respectively. Transition density plots illustrate number of transition events per second. N denotes the total number of molecules used to generate the FRET histograms from three independent experiments (n = 3). Source data are provided as a Source Data file.
