Structure of the E. coli 70S ribosome with MS2-V3 inserted in H98. (A) Model and density for the H1–H94–H98 nucleotide quartet in the WT 70S ribosome (left, PDB:7K00 EMD:22586), 70S ribosome with MS2-V2 inserted in H98 (middle, PDB:8EIU EMD:28165), and 70S ribosome with MS2-V3 inserted in H98 (right). Nucleotide A2800 is shown in pink and an additional B-factor of 15 Å2 was applied to the cryo-EM maps. (B) Overview of H98 in the WT 70S ribosome (gray, PDB:7K00) and the helix upon insertion of MS2-V3 in H98 (brown). (C) Low-pass filtered cryo-EM maps for MS2-V2 (EMD:28165) and MS2-V3 overlaid on the MS2-V3 model for H1, H94, and H98. Cryo-EM maps were low-pass filtered to 10 Å. The nucleotide equivalent to A2800 (A2833) is marked in red.
