Figure 2. Codons corresponding to lower-abundance tRNAs are decoded more slowly.

(A) Correlation between codon-specific excess ribosome densities and cognate tRNA abundances. Codons within RPFs were assigned to the A-, P-, and E-site positions based on the distance from the 5' ends of fragments, and codonspecific excess ribosome densities were calculated (v_k, Eqn S19). Cognate tRNA abundances for each codon were estimated using the genomic copy numbers of iso-accepting tRNAs and wobble parameters (Table S2). Spearman R values are shown, with their significance (p values).

(B) The correlations of codon–tRNA abundance at different positions relative to the A site. Analysis was as in (A) using varying offsets from the A-site position within RPFs (x axis) to calculate Spearman correlations (y axis).

See also Figures S2–3 and Tables S1–2.