Publication Date:
2016-02-26
Description:
The U4/U6.U5 triple small nuclear ribonucleoprotein (tri-snRNP) is a major spliceosome building block. We obtained a three-dimensional structure of the 1.8-megadalton human tri-snRNP at a resolution of 7 angstroms using single-particle cryo-electron microscopy (cryo-EM). We fit all known high-resolution structures of tri-snRNP components into the EM density map and validated them by protein cross-linking. Our model reveals how the spatial organization of Brr2 RNA helicase prevents premature U4/U6 RNA unwinding in isolated human tri-snRNPs and how the ubiquitin C-terminal hydrolase-like protein Sad1 likely tethers the helicase Brr2 to its preactivation position. Comparison of our model with cryo-EM three-dimensional structures of the Saccharomyces cerevisiae tri-snRNP and Schizosaccharomyces pombe spliceosome indicates that Brr2 undergoes a marked conformational change during spliceosome activation, and that the scaffolding protein Prp8 is also rearranged to accommodate the spliceosome's catalytic RNA network.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Agafonov, Dmitry E -- Kastner, Berthold -- Dybkov, Olexandr -- Hofele, Romina V -- Liu, Wen-Ti -- Urlaub, Henning -- Luhrmann, Reinhard -- Stark, Holger -- New York, N.Y. -- Science. 2016 Mar 25;351(6280):1416-20. doi: 10.1126/science.aad2085. Epub 2016 Feb 18.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, D-37077 Gottingen, Germany. ; Bioanalytical Mass Spectrometry, Max Planck Institute for Biophysical Chemistry, D-37077 Gottingen, Germany. Bioanalytics Group, Institute for Clinical Chemistry, University Medical Center Gottingen, D-37075 Gottingen, Germany. ; Department of 3D Electron Cryomicroscopy, Georg-August Universitat Gottingen, D-37077 Gottingen, Germany. Department of Structural Dynamics, Max Planck Institute for Biophysical Chemistry, D-37077 Gottingen, Germany. ; Bioanalytical Mass Spectrometry, Max Planck Institute for Biophysical Chemistry, D-37077 Gottingen, Germany. Bioanalytics Group, Institute for Clinical Chemistry, University Medical Center Gottingen, D-37075 Gottingen, Germany. reinhard.luehrmann@mpi-bpc.mpg.de hstark1@gwdg.de henning.urlaub@mpibpc.mpg.de. ; Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, D-37077 Gottingen, Germany. reinhard.luehrmann@mpi-bpc.mpg.de hstark1@gwdg.de henning.urlaub@mpibpc.mpg.de. ; Department of 3D Electron Cryomicroscopy, Georg-August Universitat Gottingen, D-37077 Gottingen, Germany. Department of Structural Dynamics, Max Planck Institute for Biophysical Chemistry, D-37077 Gottingen, Germany. reinhard.luehrmann@mpi-bpc.mpg.de hstark1@gwdg.de henning.urlaub@mpibpc.mpg.de.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26912367" target="_blank"〉PubMed〈/a〉
Keywords:
Cryoelectron Microscopy
;
Crystallography, X-Ray
;
DEAD-box RNA Helicases/chemistry
;
Enzyme Activation
;
HeLa Cells
;
Humans
;
Models, Molecular
;
Peptide Elongation Factors/chemistry
;
Protein Conformation
;
RNA Helicases/chemistry
;
RNA-Binding Proteins/chemistry
;
Ribonucleoprotein, U4-U6 Small Nuclear/*chemistry
;
Ribonucleoprotein, U5 Small Nuclear/*chemistry
;
Ribonucleoproteins, Small Nuclear/chemistry
;
Saccharomyces cerevisiae Proteins/chemistry
;
Schizosaccharomyces/metabolism
;
Ubiquitin Thiolesterase/chemistry
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
