RNA Catalyzed Lariat Formation from Yeast Mitochondrial Pre-Ribosomal RNA
mitochondrial introns possess conserved nucleotide blocks, which by inducing specific folding of intron RNA are thought to facilitate the splicing process (Michel and Dujon, 1983; Waring and Davies, 1984). Mutations in such sequence elements have a cis-acting phenotype (Lamouroux et al. 1980). In contrast nuclear introns in higher eukaryotes do not contain sequence elements of this type that contribute to RNA splicing (Wieringa et al. 1984).
some mitochondrial introns contain long open reading frames in phase with the upstream exon. Translation of unspliced RNA by mitochondrial ribosomes leads to synthesis of hybrid proteins (maturases), which are involved in and contribute to intron removal (Lazowska et al. 1980). This is supported by the observation that nucleotide alterations leading to a deficient reading frame can be complemented in trans by the wildtype allele (Lamouroux et al. 1980).
KeywordsSplit Gene Mitochondrial Ribosome Splice System Mitochondrial Intron Large rRNA
Unable to display preview. Download preview PDF.
- Dujon, B., 1981, Mitochondrial genetics and function, in: Life cycle and Inheritance, J.H. Strathem, E.W. Jones and J.R. Broach, eds., Cold Spring Harbor Laboratory, Cold Spring Harbor, N.Y., 505–635.Google Scholar
- Lamouroux, A., Pajot, P., Kochko, A., Halbreich, A. and Slonimski, P.P., 1980, Cytochrome b messenger RNA maturase encoded in an intron regulates the expression of the split gene: II. Trans-and cis-acting mechanisms of mRNA splicing, in: The Organization and Expression of the Mitochondrion Genome, C. Saccone and A. Kroon, eds., North-Holland, New York, 152–156.Google Scholar
- Michel, F. and Dujon, B., 1983, Conservation of RNA secondary structure in two intron families including mitochrondrial-, chloroplast-and nuclear encoded members, EMBO J., 2:33–38.Google Scholar
- Mount, S.M. and Steitz, J.A., 1984, RNA splicing and the involvement of small ribonucleoproteins, Mol. Cell. Biol., 3:249–297.Google Scholar
- Pillar, T., Lang, B.F., Steinberger, I., Vogt, B. and Kaudewitz, F., 1983, Expression of the “split gene” cob in yeast mtDNA: Nuclear mutations specifically block the excision of different introns from its primary transcript, J. Biol. Chem., 258:7954–7959.Google Scholar