A synthetic RNA editing factor edits its target site in chloroplasts and bacteria

Members of the pentatricopeptide repeat (PPR) protein family act as
specificity factors in C-to-U RNA editing. The expansion of the PPR
superfamily in plants provides the sequence variation required for design
of consensus-based RNA-binding proteins. We used this approach to design a
synthetic RNA editing factor to target one of the sites in
the Arabidopsis chloroplast transcriptome recognised by
the natural editing factor CHLOROPLAST BIOGENESIS 19 (CLB19). We show that
our synthetic editing factor specifically recognises the target sequence
in in vitro binding assays. The designed factor is equally specific for
the target rpoA site when expressed in chloroplasts and
in the bacterium E. coli. This study serves as a successful pilot
into the design and application of programmable RNA editing factors based
on plant PPR
proteins.