This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Supplemental material
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Frilander, M. J.
Right arrow Articles by Meng, X.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Frilander, M. J.
Right arrow Articles by Meng, X.

Next Article 

Molecular and Cellular Biology, June 2005, p. 4813-4825, Vol. 25, No. 12
0270-7306/05/$08.00+0     doi:10.1128/MCB.25.12.4813-4825.2005
Copyright © 2005, American Society for Microbiology. All Rights Reserved.

Proximity of the U12 snRNA with both the 5' Splice Site and the Branch Point during Early Stages of Spliceosome Assembly{dagger}

Mikko J. Frilander* and Xiaojuan Meng

Institute of Biotechnology, Program on Developmental Biology, PL56 (Viikinkaari 9), 00014 University of Helsinki, Finland

Received 4 February 2005/ Accepted 8 March 2005

U12 snRNA is required for branch point recognition in the U12-dependent spliceosome. Using site-specific cross-linking, we have captured an unexpected interaction between the 5' end of the U12 snRNA and the –2 position upstream of the 5' splice site of P120 and SCN4a splicing substrates. The U12 snRNA nucleotides that contact the 5' exon are the same ones that form the catalytically important helix Ib with U6atac snRNA in the spliceosome catalytic core. However, the U12/5' exon interaction is transient, occurring prior to the entry of the U4atac/U6atac.U5 tri-snRNP to the spliceosome. This suggests that the helix Ib region of U12 snRNA is positioned near the 5' splice site early during spliceosome assembly and only later interacts with U6atac to form helix Ib. We also provide evidence that U12 snRNA can simultaneously interact with 5' exon sequences near 5' splice site and the branch point sequence, suggesting that the 5' splice site and branch point sequences are separated by <40 to 50 Å in the complex A of the U12-dependent spliceosome. Thus, no major rearrangements are subsequently needed to position these sites for the first step of catalysis.

* Corresponding author. Mailing address: Institute of Biotechnology, Program on Developmental Biology, PL56 (Viikinkaari 9), 00014 University of Helsinki, Finland. Phone: 358-9-191-59509. Fax: 358-9-191-59366. E-mail: Mikko.Frilander{at}Helsinki.Fi.

{dagger} Supplemental material for this article may be found at http://mcb.asm.org/.

Molecular and Cellular Biology, June 2005, p. 4813-4825, Vol. 25, No. 12
0022-538X/05/$08.00+0     doi:10.1128/MCB.25.12.4813-4825.2005
Copyright © 2005, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Turunen, J. J., Will, C. L., Grote, M., Luhrmann, R., Frilander, M. J. (2008). The U11-48K Protein Contacts the 5' Splice Site of U12-Type Introns and the U11-59K Protein. Mol. Cell. Biol. 28: 3548-3560 [Abstract] [Full Text]  
  • McGrail, J. C., O'Keefe, R. T. (2008). The U1, U2 and U5 snRNAs crosslink to the 5' exon during yeast pre-mRNA splicing. Nucleic Acids Res 36: 814-825 [Abstract] [Full Text]  
  • Yang, J., Valineva, T., Hong, J., Bu, T., Yao, Z., Jensen, O. N., Frilander, M. J., Silvennoinen, O. (2007). Transcriptional co-activator protein p100 interacts with snRNP proteins and facilitates the assembly of the spliceosome. Nucleic Acids Res 35: 4485-4494 [Abstract] [Full Text]  


Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»