Involved in organellar RNA editing. Required for the processing of multiple editing sites in plastids. Homodimer and heterodimer with MORF2 (PubMed:22411807, PubMed:25583991). Interacts with protoporphyrinogen oxidase 1 PPOX1 (PubMed:24497494). Heterodimer with MORF5/RIP5 (PubMed:25583991). Interacts with PCMP-A2/PMD1 (PubMed:26123918). Interacts with ORRM6 (PubMed:28213559). White leaves with green islands, giving a variegated appearance. Mutant plants can grow autotrophically on soil. Belongs to the MORF family.