Fig. 1: Design of the stop codon reversion-based screening system.
From: Human cell based directed evolution of adenine base editors with improved efficiency
a Different EGFP variants. Single-nucleotide conversions are indicated by blue and residue substitutions are indicated by white. The stop codon was highlighted with red pentagram. b, c Fluorescence image (b) and editing efficiencies (c) of HEK-293 cells co-transfect with EGFP WT, variant, dEGFP 1 and dEGFP 2, respectively. EGFP variant maintains the expression, while dEGFP 1 and dEGFP 2 abolish the expression. (c) EGFP positive cells were quantified by flow cytometry. Scale bar, 10 μm. Data are shown as the average mean ± s.d. (n = 4 independent experiments). d, e The sequence of different sgRNAs (5-‘NG-3’ PAM) for dEGFP 1 and dEGFP 2, respectively. The stop codon and target A base have been highlighted in bold and red. f, g Editing efficiencies of A to G mutations at different positions of dEGFP 1 and dEGFP 2. Data are shown as the average mean ± s.d. (n = 3 independent experiments). Source data are available in the Source data file.
