Nucleic Acids Research, Vol 24, Issue 17 3415-3423, Copyright © 1996 by Oxford University Press
LC Shaw, J Thomas Jr and AS Lewin
The Cbp2 protein facilitates the folding of a group I intron in the COB
pre-mRNA of yeast mitochondria. Based on its ability to suppress mutations
affecting the auto-catalytic reaction, the protein appears to play a role
in the selection of splice sites. Adding Cbp2 did not overcome the effects
of mutations in P1 whose primary effect was on the first step of splicing.
In contrast, most mutations affecting the ligation of exons were suppressed
in vitro by Cbp2. These included mutations in P1, P9.0 and P10. In fact, a
mutant transcript lacking both P9.0 and P10 ligated efficiently in the
presence of Cbp2. P9.0 and P10 mutations also reduced the rate of cleavage
at the 5' splice junction, and this effect was only partially mitigated by
adding Cbp2. A competitive secondary structure near the 3' splice junction
blocked Cbp2-stimulated splicing, but this mutation could be suppressed by
co- transcriptional splicing in the presence of Cbp2. Our data underscore
the importance of the interaction between the 5' and 3' splice junctions in
group I introns and suggest that nucleotide-nucleotide interactions that
stabilize the structure of group I introns can be superceded by protein-RNA
interactions.
ARTICLES
The Cbp2 protein suppresses splice site mutations in a group I intron
Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville 32610-0266, USA.
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  H. K. Tirupati, L. C. Shaw, and A. S. Lewin An RNA Binding Motif in the Cbp2 Protein Required for Protein-stimulated RNA Catalysis J. Biol. Chem., October 22, 1999; 274(43): 30393 - 30401. [Abstract] [Full Text] [PDF]
|
|