Involved in multiple sites RNA editing events in chloroplasts. Involved in the editing of the site 9 of ndhB (ndhB-9) and site 1 of ndhG (ndhG-1) transcripts, which are two plastid-encoded subunits of the chloroplast NAD(P)H dehydrogenase (NDH) complex. Not essential for the activity of the NDH complex of the photosynthetic electron transport chain. Interacts with ORRM1 (PubMed:23487777). Interacts with VAR3/OZ1 (PubMed:25768119). No visible phenotype under normal growth conditions. The DYW motif is dispensable for editing activity in vivo. Belongs to the PPR family. PCMP-H subfamily.