Figure 3.

RNA editing and method of recognition code in RNA binding. Each PPR motif’s amino acid position 6′ and 1′ in PLS repeats is denoted by a circle. To identify the recognition site, the binding to particular mRNA bases (upstream of the edited nucleotide) is specified by amino acid combinations at positions 6′ and 1′ of PPR (T, N) (T at 6′, N at 1’) binding to guanine (G), adenine (A), cytidine (C), cytidine (D), uridine (U), and (N, N) to either C or U. Tyrosine, asparagine, aspartic acid, and serine are each represented by the letters T, N, D, and S, respectively. The DYW domain has deaminase activity to change cytosine to uracile.