Figure 4.

Mutational scanning data. (A) Partial mutational fitness landscape for E. coli TEM-1 β-lactamase, adapted from Firnberg et al. (2014). For almost all possible single mutants, fitness was assayed as relative antibiotic resistance. Gray entries denote mutations not measured, and green squares highlight the ancestral sequence. (B) Joint distribution of fitnesses for mutually nonsynonymous mutations for TEM-1 β-lactamase, using data from Firnberg et al. (2014). For other data sets in Table 1, see Figure S3.