Fig. 1
Bacterial genomes show selection to reduce nucleotide biosynthetic cost (Sc) and increase translational efficiency (St). Genome-wide values for 1320 bacterial species covering 730 genera for (a) bias towards GC (GCb). Positive values indicate bias towards GC. Negative values indicate bias towards AT. b Strength of selection acting on codon biosynthetic cost (Sc). Negative values indicate selection acting to reduce biosynthetic cost. c Strength of selection acting on codon translational efficiency (St). Positive values indicate selection acting to increase codon translational efficiency