Extended Data Figure 6: Overall distribution of rRNA and proteins in the mitochondrial 39S subunit and the bacterial 50S subunit.
From: The complete structure of the large subunit of the mammalian mitochondrial ribosome
a, Mitochondrial ribosomal large subunit (subunit interface side on the left, solvent-exposed side on the right). Proteins (cyan) almost entirely cover the solvent-exposed side of the 39S subunit, leaving barely any rRNA (orange) exposed. b, In bacterial ribosomes15 (L1 stalk omitted for clarity), a significant portion of the ribosomal surface on the solvent-exposed side is composed of rRNA (brown), with ribosomal proteins (slate blue) scattered across the subunit surface. The subunit interface side, which makes contact to the small subunit and binds tRNA substrates, is formed by rRNA to a large extent in both types of ribosomes. Landmarks are indicated: L7/L12, L7/L12 stalk base; CP, central protuberance; PTC, peptidyl transferase centre; tunnel exit, polypeptide tunnel exit site.
