Complex cis-elements determine an RNA editing site in pea mitochondria.
The cis-requirements for the first editing site in the atp9 mRNA from pea mitochondria were investigated in an in vitro RNA editing system. Template RNAs deleted 5' of -20 are edited correctly, but with decreased efficiency. Deletions between -20 and the edited nucleotide abolish editing activity. Substitution of the sequences 3' of the editing site has little effect, which suggests that the major determinants reside upstream. Stepwise mutated RNA sequences were used as templates or competitors that divide the cis-elements into several distinct regions. In the template RNAs, mutation of the sequence between -40 and -35 reduces the editing activity, while the region from -15 to -5 is essential for the editing reaction. In competition experiments the upstream region can be titrated, while the essential sequence near the editing site is largely resistant to excess competitor. This observation suggests that either one trans-factor attaches to these separate cis-regions with different affinities or two distinct trans-factors bind to these sequences, and one of which is present in limited amounts, whereas the other one is more abundant in the lysate.
Molekulare Botanik, Universität Ulm, 89069 Ulm, Germany. mizuki.takenaka@biologie.uni-ulm.de
Mizuki
M
Takenaka
Julia
J
Neuwirt
Axel
A
Brennicke
D029681:Arabidopsis Proteins; D001483:Base Sequence; D002736:Chloroplasts / Q000235:genetics; D025261:Mitochondrial Proton-Translocating ATPases / Q000235:genetics / Q000378:metabolism; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009154:Mutation; D018532:Pisum sativum / Q000235:genetics*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D011510:Proteolipids / Q000235:genetics / Q000378:metabolism; D012313:RNA / Q000737:chemistry* / Q000378:metabolism; D017393:RNA Editing; D012333:RNA, Messenger / Q000737:chemistry / Q000378:metabolism; D000077278:RNA, Mitochondrial; D018749:RNA, Plant / Q000737:chemistry* / Q000378:metabolism; D038621:Regulatory Sequences, Ribonucleic Acid; D017384:Sequence Deletion; D013698:Templates, Genetic
C063668:ATP9 protein, Arabidopsis; D029681:Arabidopsis Proteins; D010940:Plant Proteins; D011510:Proteolipids; D012333:RNA, Messenger; D000077278:RNA, Mitochondrial; D018749:RNA, Plant; D038621:Regulatory Sequences, Ribonucleic Acid; D012313:RNA; D025261:Mitochondrial Proton-Translocating ATPases