Structural requirements for selection of 5′- and 3′ splice sites of group II introns
Open Access
- 25 June 1991
- journal article
- research article
- Published by Oxford University Press (OUP) in Nucleic Acids Research
- Vol. 19 (12), 3307-3314
- https://doi.org/10.1093/nar/19.12.3307
Abstract
The group II intron bl1 in the gene for apocytochrome b in yeast mitochondrial DNA (COB) is self-splicing in vitro. It could recently be shown that self-splicing of this Intron is fully reversible in vitro. In addition, intron Integration is not restricted to parental exons, since the Intron can also integrate into a foreign RNA. The position of insertion seems to be immediately 3′ to a cryptic intron binding site 1 (IBS1). We confirmed and extended these results by sequencing 26 individual RNAs with transposed introns after reverse transcription and PCR amplification. Results show that intron integration into authentic exons is generally correct, but that integration into a foreign RNA is often inaccurate, i.e. insertion is one nt downstream or upstream of the 3′ end of IBS1. This leads to the generation of 5′ splice junctions of the new intron-harbouring “preRNAs” with addition (or deletion) of a single A residue at the 3′ end of IBS1. To investigate which structures help to define the position of 5′- and 3′ cleavage, preRNAs of i) these clones with aberrant 5′ splice junctions and ii) preRNAs with artificial hairpins between domains 5 and 6 of the intron were spliced under different reaction conditions. Results obtained let us conclude that i) branchpoint dependent 5′ cleavage is directed by the 5′ terminal G residue of the intron and, ii) the first nucleotide(s) of the 3′ exon play an important role in defining the 3′ splice site.Keywords
This publication has 18 references indexed in Scilit:
- Group II intron RNA-catalyzed recombination of RNAin vitroNucleic Acids Research, 1990
- Sequence requirements for branch formation in a group ll self-splicing lntronNucleic Acids Research, 1989
- Group II intron domain 5 facilitates a trans-splicing reaction.Molecular and Cellular Biology, 1988
- RNA as an RNA Polymerase: Net Elongation of an RNA Primer Catalyzed by the Tetrahymena RibozymeScience, 1988
- Group II intron self-splicing. Alternative reaction conditions yield novel products.Journal of Biological Chemistry, 1988
- Selection of cryptic 5′ splice sites by group II intron RNAsin vitroNucleic Acids Research, 1988
- Self-splicing of group II introns in vitro: Lariat formation and 3′ splice site selection in mutant RNAsCell, 1987
- Multiple exon-binding sites in class II self-splicing intronsCell, 1987
- Self-splicing of group II introns in vitro: Mapping of the branch point and mutational inhibition of lariat formationCell, 1986
- A self-splicing RNA excises an intron lariatCell, 1986