Figure 3.

MazF-dependent generation of stress-ribosomes. (a) The secondary structure of the Escherichia coli 16S rRNA is depicted. The helices 44 and 45 are enlarged, the ACA-site is indicated in magenta and the position of MazF cleavage between nucleotides A1499 and A1500 is indicated by an arrow. (b) The structure of the 30S subunit as seen from the solvent side. The tRNAs are shown in black, and the mRNA bound to the ribosomal subunit is shown in green. RNA43 of the 16S rRNA, which is removed upon MazF cleavage (shown in magenta), interacts via formation of the Shine and Dalgarno duplex with the mRNA. The structure was modeled using Polyview 3D molecular system software [52] and PDB file 2HGP [54].