Extended Data Fig. 4: Dri interactions with the ribosome.
From: Structure of an archaeal ribosome reveals a divergent active site and hibernation factor
a, Dri (red) binds to the rotated state of the P. calidifontis ribosome (grey). An E. coli ribosome in the unrotated state (PDB:8EMM ref. 55) is overlayed for reference (grey). b, (left) Dri residues occupy the positions of the A and P-site amino acids in the PTC. The A and P-site tRNAs from PDB:8EMM ref. 55 are overlayed on the P. calidifontis ribosome (right). Dri residue F219 occupies the A-site cleft in a position similar to phenylalanyl-tRNAPhe (PDB: 1VY4 ref. 56). c, In the absence of the Dri protein, a loop of rProtein uL16 is disordered (top). Cryo-EM density is shown in gray. Upon binding of the Dri N-terminal lobe to the LSU, the loop of uL16 becomes ordered (bottom). d, Cryo-EM density for PTC nucleotides in the 50S-Dri complex (left) or the composite 70S complex (right).
