Reconstitution of a group I intron self-splicing reaction with an activator RNA.
AUTOR(ES)
van der Horst, G
RESUMO
The self-splicing rRNA intron of Tetrahymena thermophila belongs to a subgroup of group I introns that contain a conserved extra stem-loop structure termed P5abc. A Tetrahymena mutant precursor RNA lacking this P5abc is splicing-defective under standard conditions (5 mM MgCl2/200 mM NH4Cl, pH 7.5) in vitro. However, the mutant precursor RNA by itself is capable of performing the self-splicing reaction without P5abc under different conditions (15 mM MgCl2/2 mM spermidine, pH 7.5). We have investigated the functional role of the P5abc in the mechanism of the self-splicing reaction. When an RNA consisting of the P5abc but lacking the rest of the Tetrahymena intron is incubated with the mutant precursor, the self-splicing reaction proceeds highly efficiently under standard conditions (5 mM MgCl2/200 mM NH4Cl, pH 7.5). Two steps of the bimolecular self-splicing reaction can be performed accurately by a shortened precursor RNA containing all essential components required in the self-splicing reaction and an activator RNA consisting of the P5abc. Gel-mobility-shift assays suggest that two molecules associate by a direct RNA-RNA interaction during the splicing reaction. The results imply that there might exist other small RNAs whose role is to activate ribozymes.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=50774Documentos Relacionados
- Inhibition of self-splicing group I intron RNA: high-throughput screening assays.
- Requirements for self-splicing of a group I intron from Physarum polycephalum.
- Group I Self-Splicing Intron in the recA Gene of Bacillus anthracis
- A self-splicing group I intron in the nuclear pre-rRNA of the green alga, Ankistrodesmus stipitatus.
- A Self-Splicing Group I Intron in DNA Polymerase Genes of T7-Like Bacteriophages