Figure 3.

The RNA-binding landscape of the designer PPR was examined by EMSA. (A) Schematic diagram of the modularly assembled designer PPRs. The constructed designer PPRs consisted of 10 consecutive PPR repeats containing the ‘ND’ code at the 5th and 35th positions, except repeat five and six, in which desired PPR codes were used. Sixty-two designer PPRs were constructed. (B) RNA substrates were used to determine the RNA-binding specificity of the designer PPRs. These RNAs were 5′ FAM labeled. (C) The RNA-binding specificity of designer PPRs was examined by EMSA. The final protein concentration for each sample was 1 μM. The 5th and 35th di-residues above each lane represent a designer PPR protein containing the corresponding PPR code at repeats five and six. The di-residues are arranged by distribution frequency decreasing from left to right, corresponding to Supplementary Figure S1. B: bound. U: unbound. This figure is representative of three replicates.