Pausing guides RNA folding to populate transiently stable RNA structures for riboswitch-based transcription regulation
- Johann Wolfgang Goethe-University Frankfurt am Main, Germany
- Goethe University Frankfurt, Germany
- Technical University Darmstadt, Germany
- University of Wisconsin - Madison, United States
Abstract
In bacteria, the regulation of gene expression by cis-acting transcriptional riboswitches located in the 5'-untranslated regions of messenger RNA requires the temporal synchronization of RNA synthesis and ligand binding-dependent conformational refolding. Ligand binding to the aptamer domain of the riboswitch induces premature termination of the mRNA synthesis of ligand-associated genes due to the coupled formation of 3'-structural elements acting as terminators. To date, there has been no high resolution structural description of the concerted process of synthesis and ligand-induced restructuring of the regulatory RNA element. Here, we show that for the guanine-sensing xpt-pbuX riboswitch from Bacillus subtilis, the conformation of the full-length transcripts is static: it exclusively populates the functional off-state but cannot switch to the on-state, regardless of the presence or absence of ligand. We show that only the combined matching of transcription rates and ligand binding enables transcription intermediates to undergo ligand-dependent conformational refolding.
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Funding
Deutsche Forschungsgemeinschaft (SFB902)
- Harald Schwalbe
State of Hesse (BMRZ)
- Harald Schwalbe
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2017, Steinert 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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Pausing guides RNA folding to populate transiently stable RNA structures for riboswitch-based transcription regulation
eLife 6:e21297.
https://doi.org/10.7554/eLife.21297
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