Structure of the human core transcription-export complex reveals a hub for multivalent interactions
- Research Institute of Molecular Pathology (IMP), Austria
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Austria
Abstract
The export of mRNA from nucleus to cytoplasm requires the conserved and essential transcription and export (TREX) complex (THO–UAP56/DDX39B–ALYREF). TREX selectively binds mRNA maturation marks and licenses mRNA for nuclear export by loading the export factor NXF1–NXT1. How TREX integrates these marks and achieves high selectivity for mature mRNA is poorly understood. Here we report the cryo-electron microscopy structure of the human THO–UAP56/DDX39B complex at 3.3 Å resolution. The seven-subunit THO–UAP56/DDX39B complex multimerizes into a 28-subunit tetrameric assembly, suggesting that selective recognition of mature mRNA is facilitated by the simultaneous sensing of multiple, spatially distant mRNA regions and maturation marks. Two UAP56/DDX39B RNA helicases are juxtaposed at each end of the tetramer, which would allow one bivalent ALYREF protein to bridge adjacent helicases and regulate the TREX–mRNA interaction. Our structural and biochemical results suggest a conserved model for TREX complex function that depends on multivalent interactions between proteins and mRNA.
Data availability
Three-dimensional cryo-EM density maps A, B, C, D, and E have been deposited in the Electron Microscopy Data Bank under the accession numbers EMD-11853, EMD-11857, EMD-11854, EMD-11855, EMD-11856, respectively. The coordinate file of the human THO-UAP56 complex has been deposited in the Protein Data Bank under the accession number 7APK.
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Three-dimensional cryo-EM density map AElectron Microscopy Data Bank, EMD-11853.
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Three-dimensional cryo-EM density map BElectron Microscopy Data Bank, EMD-11857.
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Three-dimensional cryo-EM density map CElectron Microscopy Data Bank, EMD-11854.
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Three-dimensional cryo-EM density maps DElectron Microscopy Data Bank, EMD-11855.
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Three-dimensional cryo-EM density maps EElectron Microscopy Data Bank, EMD-11856.
Article and author information
Author details
Funding
Boehringer Ingelheim
- Clemens Plaschka
Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung (P2GEP3_188343)
- Ulrich Hohmann
H2020 European Research Council (ERC-2015-CoG 682181)
- Julius Brennecke
Austrian Science Fund (F4303 and W1207)
- Julius Brennecke
Österreichischen Akademie der Wissenschaften
- Julius Brennecke
H2020 European Research Council (ERC-2020-STG 949081)
- Clemens Plaschka
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2020, Pühringer et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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Structure of the human core transcription-export complex reveals a hub for multivalent interactions
eLife 9:e61503.
https://doi.org/10.7554/eLife.61503
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