Fig. 4
a Interaction between part of the native and rationally designed cpxQmut1 (marked green) and the 5’UTR(T7) (marked red). Gibbs free energy (ΔG) of the interaction is depicted. The secondary RNA structure of both the native and rationally designed cpxQmut1 with ΔG-value are also illustrated. b Designs of control plasmid without engineered cpxQ sequence and plasmid with cpxQmut1 sequence controlled by the inducible promoter PBAD. c Bar plots representing the output sfGFP/OD600 for the control plasmid (blue) and the plasmid expressing the sRNA cpxQmut1 (grey) and this for different L-arabinose concentrations. sfGFP/mKate2 values for an equal number (OD600 = 0.4, mid-exponential phase) of Escherichia coli DH10B cells are plotted. All experiments were carried out in replica triplicates (biological variation) and the error bars represent one standard deviation from the mean value. * = p-value < 0.05, *** = p-value < 0.001 obtained by conducting a two-sample t-test between strains expressing the control plasmid and strain expressing the sRNA cpxQmut1 and this for each L-arabinose concentration, araC regulator of the PBAD promoter, mKate2 red fluorescent protein, OD600 optical density measured at 600 nm, pBR322 medium-copy origin of replication (~ 15–20 copies per cell), RBS ribosome binding site, sfGFP superfolder green fluorescent protein, 5’UTR(T7) 5’ untranslated region of T7 expression system, sRNA = small RNA, TIR translation initiation region, ss secondary structure