RNA editing is essential for compensating for defects or mutations in haploid organelle genomes and is regulated by numerous
trans-factors. Pentatricopeptide repeat (PPR) proteins are the prime factors that are involved in RNA editing; however, many have not yet been identified. Here,
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RNA editing is essential for compensating for defects or mutations in haploid organelle genomes and is regulated by numerous
trans-factors. Pentatricopeptide repeat (PPR) proteins are the prime factors that are involved in RNA editing; however, many have not yet been identified. Here, we screened the plastid-targeted PLS-DYW subfamily of PPR proteins belonging to
Arabidopsis thaliana and identified ORGANELLE TRANSCRIPT PROCESSING 970 (OTP970) as a key player in RNA editing in plastids. A loss-of-function
otp970 mutant was impaired in RNA editing of
ndhB transcripts at site 149 (
ndhB-C149). RNA-immunoprecipitation analysis indicated that OTP970 was associated with the
ndhB-C149 site. The complementation of the
otp970 mutant with OTP970 lacking the DYW domain (OTP970
∆DYW) failed to restore the RNA editing of
ndhB-C149.
ndhB gene encodes the B subunit of the NADH dehydrogenase-like (NDH) complex; however, neither NDH activity and stability nor NDH-PSI supercomplex formation were affected in
otp970 mutant compared to the wild type, indicating that alteration in amino acid sequence is not necessary for NdhB function. Together, these results suggest that OTP970 is involved in the RNA editing of
ndhB-C149 and that the DYW domain is essential for its function.
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