Projects per year
Abstract
PaaR2 is a putative transcription regulator encoded by a three-component parDE-like toxin-antitoxin module from Escherichia coli O157:H7. Although this module's toxin, antitoxin, and toxin-antitoxin complex have been more thoroughly investigated, little remains known about its transcription regulator PaaR2. Using a wide range of biophysical techniques (circular dichroism spectroscopy, size-exclusion chromatography-multiangle laser light scattering, dynamic light scattering, small-angle x-ray scattering, and native mass spectrometry), we demonstrate that PaaR2 mainly consists of α-helices and displays a concentration-dependent octameric build-up in solution and that this octamer contains a global shape that is significantly nonspherical. Thermal unfolding of PaaR2 is reversible and displays several transitions, suggesting a complex unfolding mechanism. The unfolding data obtained from spectroscopic and calorimetric methods were combined into a unifying thermodynamic model, which suggests a five-state unfolding trajectory. Furthermore, the model allows the calculation of a stability phase diagram, which shows that, under physiological conditions, PaaR2 mainly exists as a dimer that can swiftly oligomerize into an octamer depending on local protein concentrations. These findings, based on a thorough biophysical and thermodynamic analysis of PaaR2, may provide important insights into biological function such as DNA binding and transcriptional regulation.
Original language | English |
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Pages (from-to) | 1420-1431 |
Number of pages | 12 |
Journal | Biophysical Journal |
Volume | 116 |
Issue number | 8 |
DOIs | |
Publication status | Published - 23 Apr 2019 |
Bibliographical note
Copyright © 2019 Biophysical Society. Published by Elsevier Inc. All rights reserved.Keywords
- Toxin-antitoxin module
- Transcription factors
- Molecular biophysics
- Protein chemistry
Fingerprint
Dive into the research topics of 'Thermodynamic stability of the transcription regulator PaaR2 from Escherichia coli O157:H7'. Together they form a unique fingerprint.Projects
- 3 Finished
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FWOAL831: Regulation of persistence by the paaAR-paaA2-parE2 and cog4197-duf1019 operons from E. coli O157
1/01/17 → 31/12/20
Project: Fundamental
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FWOTM637: New mechanisms of transcription regulation in prokaryotes
1/10/12 → 30/09/16
Project: Fundamental
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Bistable expression of a toxin-antitoxin system located in a cryptic prophage of Escherichia coliO157:H7
Jurenas, D., Fraikin, N., Goormaghtigh, F., De Bruyn, P., Vandervelde, A., Jove, T., Charlier, D., Loris, R. & Van Melderen, L., 21 Dec 2021, In : mBio. 12, 6, 15 p., e0294721.Research output: Contribution to journal › Article
Open Access -
Nanobody-aided crystallization of the transcription regulator PaaR2 from Escherichia coli O157:H7
De Bruyn, P., Prolic Kalinsek, M., Vandervelde, A., Malfait, M., Sterckx, Y., Sobott, F., Hadzi, S., Pardon, E., Steyaert, J. & Loris, R., 1 Oct 2021, In : Acta Crystallographica Section F - Structural Biology Communications. 77, 10, p. 374-384 11 p., 11.Research output: Contribution to journal › Article
Open AccessFile6 Downloads (Pure) -
Toxin-antitoxin modules: functional characterization of transcription regulation and potential use against pathogenic bacteria
De Bruyn, P., 2021, Brussels.Research output: Thesis › PhD Thesis