Fig. 3: The amino acid distribution observed in deep sequencing of the activity-sorted MKK1 variants.

a Proportional Venn diagram displaying the number of unique sequences found in the low activity gate (≥3 sequencing reads, red), medium activity gate (≥5 sequencing reads, yellow) and the high-activity gate (≥10 sequencing reads, green). b The enrichment of observed amino acids (\({f}_{a}^{{obs}}\)) at each position in the final active set of n = 29,563 variants found in the high gate, relative to expected frequencies (\({f}_{a}^{{id}}\)) in a perfectly balanced library.