Figure 1.

Overview of the RelE-Bound 70S Ribosome

(A) Top view of the 70S ribosome with the 50S (blue) and 30S (wheat) subunits surrounding RelE (A site, blue), tRNA^fMet (P site, green), a noncognate tRNA^fMet (E site, red), and mRNA (magenta). (A)–(C) are based on the precleavage structure.

(B) Close-up of the A and P sites of the 30S subunit viewed from the interface to the 50S. RelE (blue cartoon) spans the 16S rRNA from the head (helix 31 region, green) to the body (helix 18, pink). The mRNA is shown in purple sticks, and the P and E site tRNAs colored as in (A).

(C) Close-up view of the A and P sites showing RelE (blue Cα trace), mRNA (purple sticks), and P site tRNA (green cartoon) along with the DF_o-mF_c electron density of the precleavage structure contoured at 1.5 σ. The mRNA sequence is indicated.

(D) The postcleavage structure showing the position of the 2′-3′ cyclic phosphate generated upon cleavage (2′-3′ cP). The map is contoured at 1.2 σ.

See also Figure S1.