Specificity of four SpeCas9 variants.

(A) Schematic of SpeCas9 structure. The amino acid residues important for specificity are shown below. (B) Test of four SpeCas9 variant specificity. Schematic of the GFP activation assay for specificity analysis is shown on the top. A panel of sgRNAs with dinucleotide mutations is shown below. sgRNA activities were measured based on GFP expression. Cells without Cas9 transfection were used as a negative control (NC). Mismatches are shown in red (n = 3). Underlying data for all summary statistics can be found in S1 Data. (TIF)