INVOLVEMENT OF 5'-FLANKING SEQUENCE FOR SPECIFYING RNA EDITING SITES IN PLANT-MITOCHONDRIA

Unsuccessful insertion of foreign DNA into plant mitochondrial genomes has hindered scientific evaluation of cis-elements needed for RNA edi ting. Both a normal atp6 gene and a chimeric atp6 sequence are present in rice mitochondria. The chimeric atp6 contains one-half of the norm al atp6 sequence in its 5' portion and an unknown sequence in its down stream portion. The C-nucleotide at position 511, located just upstrea m of the unknown sequence recombined in the chimeric atp6 sequence, is edited, as are other possible editing sites upstream from position 51 1. We report here that the 5' sequence adjacent to the editing site of atp6 contains cis-information required for RNA editing and that the 3 ' sequence flanking the editing site provides little contribution to e diting-site recognition. (C) 1997 Federation of European Biochemical S ocieties.