FIGURE 1.

Schematic illustration of the positions of expansion segments ES3 (black) and ES6 (dark gray) on the yeast 40S ribosomal subunits (Spahn et al. 2001) and in the secondary structure model of 18S rRNA (Comparative RNA Web site; http://www.rna.icmb.utexas.edu/; Cannone et al. 2002). The 40S subunit is viewed from the interface side (left) and from the solvent side (right). (Insets) Secondary structure models for yeast ES3 and ES6 (The European ribosomal RNA database, http://oberon.rug.ac.be:8080/rRNA/; Wuyts et al. 2002). The nucleotides are numbered in accordance with Figure 2 ▶. The proposed tertiary interaction between sequences in yeast ES3 and ES6 is based on the consensus sequences (Alkemar and Nygard 2003).