Fig. 1.

Global view of protein uL3 in the context of the ribosome. Localization and folding of the protein uL3 in the ribosome. Figures were generated by using the structure of the S. cerevisiae vacant wild-type ribosome (PDB 4V88) [12] with A- and P-site aa-tRNAs extracted from the superimposed Thermus thermophilus structure (PDB 4V5D) [19]. (a) Schematic top and A site views of the translating ribosome. The large ribosomal subunit is represented in gray, the small ribosomal subunit in blue, the A-site tRNA in yellow, the P-site tRNA in orange, the E-site tRNA in red, the PTC in green, and ribosomal protein uL3 in purple. (b) Structure of the protein uL3 in the context of the ribosome. uL3 folds as a 3-fingered platform formed by its globular domain (in deep purple), and the N-terminal extension (in light blue), the “tryptophan finger” (W finger; in wheat), and the “basic thumb” (in pale green). Those 3 “fingers” extend into the central core of the LSU, their tips reaching less than 12 Å away from the PTC (in green).