Fig. 5. Analysis of the number and types of amino acid substitutions present at each position of the saturation editing libraries can be used to identify important residues.

The distribution of tolerance scores, i.e. how tolerant each residue is towards substitutions with different amino acids, is shown for FabZ (a), LpxC (b) and MurA (c). The relative solvent accessibility (RSA) is plotted in function of the tolerance score for each residue of FabZ (d), LpxC (e) and MurA (f). Residues with the lowest tolerance scores and low RSA are colored black and are likely essential for protein folding and stability. The residues with the lowest tolerance scores and relatively high RSA are highlighted in orange and likely play an important and direct role in protein function. Source data are provided as Supplementary Data 5.