Abstract
RNA editing is a process modifying the genetic information on RNA molecules and is a conversion of C to U in higher plants. For the site recognition, the sequence surrounding the editing site is essential. There are not strict consensus sequences among these cis-elements and each editing site is independently recognized by a different trans-factor. From the characterization of Arabidopsis mutants defective in photosynthetic electron transport, a PPR protein was shown to be a trans-factor in plastid RNA editing. The PPR family consists of approximately 500 members in higher plants. This large family size may relate to the high frequency of RNA editing in plant organelles. Members of the family are involved in a variety of RNA maturation processes except for RNA editing. How did some members become involved in RNA editing?
