Figure 2. Adenine depletion in SSCRs is attenuated by 5UIs.

All bars represent the average from the first 69 nucleotides of all SSCRs-containing open reading frames from the human genome which either lacked (“−“) or had (“+”) 5UIs. As controls, these sequences were compared to the rest of the open reading frame, or analogous regions from open reading frames that lacked SSCRs (“other”). Error bars correspond to standard errors of the median or mean, as appropriate. (A) Median adenine percentage. Standard error of the median was determined by bootstrap-resampling. (B) The mean ratio between the number of encoded leucines to isoleucines. (C) The mean ratio between the number of encoded arginines to lysines. (D) The ratio of adenine- lacking, to adenine-containing codons for all amino acids that have both types of codons (L, V, A, P, S, G, and R). See Figure S3 for examples of adenine codon bias for specific amino acids (leucine and serine).