Figure 1.

Ribosome chimerism in the protoeukaryotic cell. RPs that were transferred to the host genome in the eukaryotic stem lineage are highlighted in red in the structure of the Thermus thermophilus 70S ribosome (A) large (B) and small (C) subunits (PDB codes 2J03 and 2J02). The small subunit 16S RNA and proteins are coloured in blue, 23S RNA in grey, large subunit proteins in green, A-, P- and E-site tRNAs in magenta. The ancestrally host-encoded proteins are labelled, L33 and L35 are on the other side of the structure.