Extended Data Fig. 1: The on-target editing ofthe BE3 and BE3 variants in different target sites.

a, The mutated residues are highlighted in the predicted structure of rAPOBEC1. Green and yellow colors indicate residues in the helix and the loop of the structure, respectively. b, The crystal structure of APOBEC3G. c, The on-target efficiency and indel frequencies of different versions of engineered CBEs for additional 11 target sites. d, The C-to-T editing efficiency for the engineered variants at each C of the 21 target sites. n = 21 independent experiments for each group. All values are presented as mean ± s.e.m. e, The indel frequency comparison among the engineered variants for the 21 target sites. n = 21 independent experiments for each group. P value was calculated by two-sided Student’s t-tests. Box-and-whisker plots: center line indicates median, the bottom and top lines of the box represents the first quartile and third quartile of the values, respectively. The bottom and top of the vertical line represent the minimum and maximum value. f, The on-target C-to-T editing efficiency of engineered BE3 variants at each target site. n = 3 biologically independent samples for each group. P value was calculated by two-sided Student’s t-tests. Sequences of the on-target protospacers and primers were shown in Extended Data Table 5. The data for BE3 and YE1-BE3 are also used in Figs. 3a and 3d-g.