| Autor: |
Emerick VL; Department of Chemistry and Biochemistry, University of Maryland, College Park 20742-2021, USA., Pan J, Woodson SA |
| Jazyk: |
angličtina |
| Zdroj: |
Biochemistry [Biochemistry] 1996 Oct 15; Vol. 35 (41), pp. 13469-77. |
| DOI: |
10.1021/bi960865i |
| Abstrakt: |
RNA catalyzed reactions are often limited in vitro by the rate of structural rearrangements in the RNA. Analysis of intra- and intermolecular splicing of the Tetrahymena preribosomal RNA revealed two well resolved kinetic phases with rate constants of approximately 2.5 and 0.02 min-1 at 30 degrees C. The data are consistent with a model in which the second phase results from slow refolding of the pre-rRNA. Point mutations result in redistribution of the RNA among different conformations that can be detected by native gel electrophoresis. The active pre-rRNA rapidly progresses to a product complex in the presence of GTP. Release of the ligated exons is slightly slower than splicing at 30 degrees C (0.3 -0.5 min-1). In contrast, the intermediate complex after the first step of splicing dissociates much more slowly (5 x 10(-3) min-1), accounting for the low amount of intron-3' exon intermediate typically seen during splicing of wild type pre-rRNA. These results provide an initial framework for studying conformational changes that accompany excision of the Tetrahymena intron from ribosomal RNA. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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