FIGURE 5.
Three-dimensional positions of the universal nucleotides in 16S rRNA. The positions of the invariant nucleotides (C = 2.000) are shown in yellow in the context of the 2.0 Å resolution cryo-EM structure of the 16S rRNA (A,B) and the 30S ribosomal subunit (C,D) in the E. coli 70S ribosome (Watson et al. 2020). The 16S rRNA (cyan) and proteins (blue) are shown in surface rendering. (A,C) Subunit interface view. (B,D) Solvent view. Many of the invariants are clustered at sites known to participate in ribosome function, as indicated in Figure 6 and Table 3. Almost no invariant nucleotides are exposed on the solvent face of 16S rRNA.
