Figure 2 - full size

Figure 2.
Figure 2. Details of the PY-binding site within the ribosome. (a) Stereo view of the location of critical 16S rRNA residues G926, C1400, C1402 and A1493 (green) relative to PY. Helix 69 (H69) of 23S rRNA is blue. Conserved residues within PY are magenta^3. (b) Overlap of PY with A- and P-site tRNAs. A-, P- and E-site tRNAs are cyan, green and gray, respectively. The positions of the 30S and 50S subunits, the path of mRNA, and the location of the C-terminal tail of PY are indicated. (c) Overlap of the difference electron density corresponding to PY with mRNA (red). The positive density, E-, A- and P-site tRNAs are color-coded as above. The negative density is not shown for clarity. The 5' and 3' ends of the mRNA are marked.