Genetic Dissection of an RNA Enzyme
This extract was created in the absence of an abstract.
Excerpt
The Group I Introns
The group I introns are characterized by short conserved sequences and a highly conserved secondary structure. Several members of this class of introns have been shown to be capable of self-splicing in vitro, without the participation of any proteins. The best-characterized example of a self-splicing group I intron is the intron from the nuclear rRNA genes of Tetrahymena thermophila, originally shown to be self-splicing by Cech and his colleagues (Kruger et al. 1982; Zaug et al. 1983).
The group I introns show a remarkably wide phylogenetic distribution. They are found in fungal mitochondria, chloroplasts, nuclear genes of ciliates, and T-even bacteriophages. The ability to compare widely differing sequences has been a great help in studies of the secondary structure of these introns. Similar models of the secondary structure of the group I introns were proposed by three groups on the basis of limited phylogenetic comparison data...
