FIGURE 6.
Model for toxin recognition of the ribosome. (A) Overlay of Initiation factor 1 (IF1, pink) and HigB (green) bound to 30S subunit. The IF1 protein is shown as a surface representation to highlight the extensive overlap between HigB and IF1. The 30S-IF1 structure (PDB code 1HR0) was aligned to the 30-HigB structure by least-squares fitting of 16S rRNA. (B) HigB can target a 30S initiation-competent complex but not in the presence of IF1. (C) The YafO toxin cleaves mRNA at the downstream mRNA entrance tunnel and not in the A site as other ribosome-dependent toxins in contrast to HigB, YafQ, YoeB, and RelE and during the translation cycle.
