FIGURE 4.

Riboswitch function by a yjdF RNA is activated by azaaromatic compounds. (A) Sequence and secondary structure of the regulatory region of the riboswitch–reporter construct generated by fusing the yjdF motif RNA from B. subtilis with the lacZ gene from E. coli. (B) Agar-diffusion assays wherein plates were inoculated with either WT or YjdF KO cells as indicated. Filter disks were infused with 10 µL of (1) staurosporine (10 mM), (2) harmane (100 mM), (3) harmine (100 mM), (4) norharmane (100 mM), (5) chelerythrine (1 mM), or (6) proflavine (10 mM).