site-specific factor interacts directly with its cognate RNA editing site in chloroplast transcripts

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 101; no. 1; pp. 48 - 52
• Main Authors: Miyamoto, T, Obokata, J, Sugiura, M
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 06.01.2004; National Acad Sciences
• Subjects: Base Sequence; binding sites; Binding Sites - genetics; Biochemistry; Biological Sciences; Chloroplast RNA; Chloroplasts; Chloroplasts - genetics; Chloroplasts - metabolism; Codons; Flowers & plants; Genes, Plant; Genetic Complementation Test; Genetic mutation; Genetics; Messenger RNA; Models, Biological; Mutation; Nicotiana - genetics; Nicotiana - metabolism; Nicotiana tabacum; Nucleotides; petB gene; Plant Proteins - genetics; Plant Proteins - metabolism; psbE gene; Research universities; Ribonucleic acid; RNA; RNA Editing; RNA, Messenger - genetics; RNA, Messenger - metabolism; RNA, Plant - genetics; RNA, Plant - metabolism; RNA-binding proteins; structural genes; tobacco; Transactivators
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.0307163101

RNA editing involves a variety of genetic systems and occurs by different mechanisms. In higher plant chloroplasts, specific sites of some transcripts are subject to C-to-U conversion. We have previously shown that site-specific trans-acting factors for psbE and petB mRNA editing bind corresponding cis-elements, which are located 5 nucleotides upstream from the editing site. Here we report that, by using mRNAs labeled either at the center of the upstream cis-element or at the editing site, the site-specific factors can be cross-linked with nucleotides at both positions. Mutations of nucleotides in the proximal region of the editing site revealed a correlation between editing activity and cross-linking efficiency of factors with the editing site, even though cross-linking with the upstream cis-element was unaffected. These observations suggest that the site-specific factor binds stably to the upstream cis-element, whereas it interacts weakly with the editing site. This finding raises the intriguing possibility that the site-specific factor is involved in both site-determination and C-to-U conversion in chloroplast RNA editing.