Local structures affecting ribosome density. A) Coefficient of variation of ribosome densities of 61 codons located from -45 to +45 nts. Positions relative to the A-site are displayed along the horizontal axis, and the corresponding ribosomal A-, P-, and E-site are designated A, P, and E, and the read-end position is indicated by the J. Solid line: Cm, Dotted line: Tet. (B) High ribosome density of G-rich triplets located from -15 to -18 positions. Relative ribosome densities of triplets in samples from cultures treated with Cm or Tet that showed the highest similarity (-16 for Cm and -17 for Tet) are shown, and triplets with high densities are marked. (C) The relative ribosome densities of codons at the E-site (-6) of samples taken from cultures treated with Cm (average ± SD) are aligned according to the molecular weight of encoded amino acid side chain.