Figure 3: Free folding energies in different codon residues.
Free folding energies (FFE) were determined in phase-selected sub-sequences of 81 genes. The original nucleic acids contained intact three-letter codons (1st+2nd+3rd). Sub-sequences were constructed by periodic removal of one letter from the codon and maintaining the other two (1st+2nd, 1st+3rd, 2nd+3rd), or removing two letters and maintaining only one (1st, 2nd, 3rd). Distinctions were made between exons (B and D) and the preceding (-1, A) and following (+1, C) sequences (introns). The dG values were determined using mfold and the FFE was calculated. Each bar represents the mean ± SEM, n=81 [6].