Figure 4.

Ribosomal proteins and nucleotides in 18S rRNA cross-linked to 4-thioU or 6-thioG at [⁻3] or [⁺4] of mRNA in 48S complexes mapped onto corresponding ribosomal proteins and regions of 16S rRNA (gray) in the crystal structure of a complex of mRNA (blue) and the T. thermophilus 30S subunit (Yusupova et al. 2001). T. thermophilus rpS19 and rpS7 correspond to eukaryotic rpS15 and rpS5 and are red and magenta, respectively. Other ribosomal proteins are light blue. The mRNA nucleotides at [⁺4] and [⁻3] are red and magenta, respectively. Positions of nucleotides in 16S rRNA that correspond to C₁₆₉₆ and AA_1818–1819 of 18S rRNA are shown as green and red spheres, respectively.