Figure 4.

Evolution of anticodon recognition region of sTyrRS. (A) The structure of sulfotyrosine (sTyr). (B) Mutations in the anticodon recognition region of evolved sTyrRS mutants. (C) GFP fluorescence assays of cells expressing sTyrRS variants. Fluorescence readings of E. coli GeneHogs cells expressing wild type (sTyrRS-wt) or the evolved mutants, each coexpressed with MjtRNA_CUA^Tyr, in the presence (blue column) or the absence (red column) of 1 mM sTyr. Fluorescence intensity was normalized to cell growth. Each data point is the average of duplicate measurements with standard deviation.