Comparison of VmlR and EttA on the ribosome. (A–C) Relative position of VmlR (orange) and P/V-tRNA (green) (A), EttA (blue, PDB ID code 3J5S) (11) and P-tRNA (cyan) (B), and superimposition of A and B (C). (D) Comparison of P/V-tRNA (green), P-tRNA (cyan), A-tRNA (brown) (39), and A/T-tRNA (pink, PDB ID code 4V5G) (40). (E) Stacking interaction (indicated by black lines) of Trp223 of VmlR (orange) with 23S rRNA nucleotide A2602 (gray), which forms hydrogen bonds (dashed lines) with U2593. (F) Conformation of VmlR bound conformation of A2602 (gray) compared with the A2602 (slate) conformation in the pretranslocation state conformation (39) with P-tRNA (cyan) and A-tRNA (data not shown).