Plays a major role in chloroplast RNA editing. Acts as a site-recognition transacting factor to recruit C-deaminase (PubMed:15662426, PubMed:17015439). Involved in single RNA editing events. Required for the edition of the site 1 of ndhD (ndhD-1 site corresponding to cytidine-2), which is a plastid-encoded subunit of the NADH-plastoquinone oxidoreductase. The interaction with DYW1 is required for its function in editing the ndhD-1 site (PubMed:23001034). Interacts with DYW1. Unlike other RNA editing factors, CCR4 does not contain identifiable E(+) and DYW motifs but does contain PPR repeats. Therefore its association with DYW1, which lacks PPR repeats, but does contain E(+) and DYW motifs, is required for its function in RNA editing. Belongs to the PPR family. PCMP-E subfamily. Truncated N-terminus.