Fig 2
Different tRNA sparing strategies alter a species’ codon cost-efficiency trade-off. a Codon nitrogen cost (N cost) correlates almost perfectly with codon energetic cost (p < 0.05, y = 0.6x + 0.44, R2 = 0.98). b A full complement of tRNAs has a negative correlation between codon biosynthetic cost and translational efficiency (tAI) (p < 0.05, y = − 0.5x + 1.21, R2 = 0.10). c tRNA sparing strategy 1 (NNU codons translated by GNN anticodons) has a positive correlation between codon biosynthetic cost and translational efficiency (p < 0.05, y = 0.9x – 0.06, R2 = 0.18). d tRNA sparing strategy 2 (strategy 1 + NNG codons translated by UNN anticodons) has no significant correlation between codon biosynthetic cost and translational efficiency (p > 0.05, y = 0.74, R2 = 0). e None of the 1320 bacterial species in this analysis have a significant negative correlation between codon cost and translational efficiency (p > 0.05). The y-axis is the gradient of the line of best fit between codon biosynthetic cost and translational efficiency