Abstract
RNA editing is a post-transcriptional process that alters specific cytidine to uridine in the mitochondrial and chloroplast transcripts of higher plants and occurs frequently. Specific target C sites are recognized by pentatricopeptide repeat (PPR) proteins that bind to the RNA upstream of the C to be edited. However, as remarked in previous work, editing sites requiring the same factor do not show extensive sequence identity in this crucial region, rasing doubts as to how these editing specificity factors recognize their target sites more than one site. To investigate the question, we undertook a systematic biochemical analysis for the factors that recognize them. The result suggests that PPR protein can specifically bind to the target sequences with almost the same binding affinity although they do not show sequence identity.
