Figure 10.

Model for translational repression of IS200 tnpA. 30S ribosomal subunit binding to tnpA is inhibited by art200 (purple) and Hfq (green) as well as RNA secondary structure which sequesters the Shine-Dalgarno sequence (SD, light blue line). Art200 and Hfq may act to (i) block ribosomal protein S1 binding to a translational enhancer or (ii) simply prevent the 30S-SD interaction. An alternative secondary structure of tnpA where the anti-Shine-Dalgarno (anti-SD, red line) is not paired to the SD is derived from secondary structure predictions (see Supplementary Figure S8). See discussion for more details.