(A) Secondary structures of rRNA A-sites of E. coli (left) and of eukaryotes (right). The conserved residues, A1492
and A1493 (E. coli numbering), are highlighted in
blue and red, respectively. (B) Superimposition of G418 bound to the E. coli A-site (green, PDB code 1MWL)20 and the S. serevisiae A-site (magenta, PDB code 4U4O),8 using the PyMol software align algorithm (r.m.s.d. = 1.5
Å). (C) Expansion of the panel B highlighting different interactions
of G418 ring I in the E. coli (green) and the S. serevisiae (magenta). The relevant H-bond interactions
are shown by dashed lines with the bond lengths in the same color.