Article abstract
Nature Structural & Molecular Biology 15, 1206 - 1212 (2008)
Published online: 26 October 2008 | doi:10.1038/nsmb.1506
Localization of Prp8, Brr2, Snu114 and U4/U6 proteins in the yeast tri-snRNP by electron microscopy
Irina Häcker1,5, Bjoern Sander2,5, Monika M Golas2,5, Elmar Wolf1, Elif Karagöz1,3, Berthold Kastner1, Holger Stark2,4, Patrizia Fabrizio1 & Reinhard Lührmann1
Abstract
The U4/U6-U5 tri–small nuclear ribonucleoprotein (snRNP) is a major, evolutionarily highly conserved spliceosome subunit. Unwinding of its U4/U6 snRNA duplex is a central event of spliceosome activation that requires several components of the U5 portion of the tri-snRNP, including the RNA helicase Brr2, Prp8 and the GTPase Snu114. Here we report the EM projection structure of the Saccharomyces cerevisiae tri-snRNP. It shows a modular organization comprising three extruding domains that contact one another in its central portion. We have visualized genetically tagged tri-snRNP proteins by EM and show here that U4/U6 snRNP forms a domain termed the arm. Conversely, a separate head domain adjacent to the arm harbors Brr2, whereas Prp8 and the GTPase Snu114 are located centrally. The head and arm adopt variable relative positions. This molecular organization and dynamics suggest possible scenarios for structural events during catalytic activation.
- Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, D-37077 Göttingen, Germany.
- Three-dimensional Electron Cryo-Microscopy Group, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, D-37077 Göttingen, Germany.
- Department of Chemistry, Utrecht University, Padualaan 8, NL-3584 CH Utrecht, The Netherlands.
- Three-dimensional Cryo-Electron Microscopy, Göttinger Zentrum für Molekulare Biologie, Universität Göttingen, Justus-von-Liebig-Weg 11, D-37077 Göttingen, Germany.
- These authors contributed equally to this work.
Correspondence to: Reinhard Lührmann1 e-mail: Reinhard.Luehrmann@mpi-bpc.mpg.de
MORE ARTICLES LIKE THIS
These links to content published by NPG are automatically generated.
NEWS AND VIEWS
Modifications target spliceosome dynamicsNature Structural & Molecular Biology News and Views (01 May 2008)
Eye on RNA unwindingNature Structural & Molecular Biology News and Views (01 Jan 2009)
See all 6 matches for News And ViewsRESEARCH
Hierarchical, clustered protein interactions with U4/U6 snRNA: a biochemical role for U4/U6 proteinsThe EMBO Journal Article (15 Oct 2002)
Composition and three-dimensional EM structure of double affinity-purified, human prespliceosomal A complexesThe EMBO Journal Article (21 Mar 2007)
See all 79 matches for Research
