Fig. 3.—

Mutational impact on DNA flexibility and frequency of occurrence for different classes of substitutions in the yeast genomes. (A) Average mutational impact of single-base substitutions on the flexibility of codon phosphate linkages (delta TRX) for all classes of substitutions. Negative values indicate mutational shifts toward increased DNA flexibility. (B) Frequencies of the same classes of substitutions for both functional (amino acid replacing) and silent substitution types. High frequency mutations (synonymous Ts) have strong counteracting average effects on DNA flexibility.