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Gubensäk N, Sagmeister T, Buhlheller C, Geronimo BD, Wagner GE, Petrowitsch L, Gräwert MA, Rotzinger M, Berger TMI, Schäfer J, Usón I, Reidl J, Sánchez-Murcia PA, Zangger K, Pavkov-Keller T. Vibrio cholerae's ToxRS bile sensing system. eLife 2023; 12:e88721. [PMID: 37768326 PMCID: PMC10624426 DOI: 10.7554/elife.88721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Accepted: 09/27/2023] [Indexed: 09/29/2023] Open
Abstract
The seventh pandemic of the diarrheal cholera disease, which began in 1960, is caused by the Gram-negative bacterium Vibrio cholerae. Its environmental persistence provoking recurring sudden outbreaks is enabled by V. cholerae's rapid adaption to changing environments involving sensory proteins like ToxR and ToxS. Located at the inner membrane, ToxR and ToxS react to environmental stimuli like bile acid, thereby inducing survival strategies for example bile resistance and virulence regulation. The presented crystal structure of the sensory domains of ToxR and ToxS in combination with multiple bile acid interaction studies, reveals that a bile binding pocket of ToxS is only properly folded upon binding to ToxR. Our data proposes an interdependent functionality between ToxR transcriptional activity and ToxS sensory function. These findings support the previously suggested link between ToxRS and VtrAC-like co-component systems. Besides VtrAC, ToxRS is now the only experimentally determined structure within this recently defined superfamily, further emphasizing its significance. In-depth analysis of the ToxRS complex reveals its remarkable conservation across various Vibrio species, underlining the significance of conserved residues in the ToxS barrel and the more diverse ToxR sensory domain. Unravelling the intricate mechanisms governing ToxRS's environmental sensing capabilities, provides a promising tool for disruption of this vital interaction, ultimately inhibiting Vibrio's survival and virulence. Our findings hold far-reaching implications for all Vibrio strains that rely on the ToxRS system as a shared sensory cornerstone for adapting to their surroundings.
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Affiliation(s)
- Nina Gubensäk
- Institute of Molecular Biosciences, University of GrazGrazAustria
| | - Theo Sagmeister
- Institute of Molecular Biosciences, University of GrazGrazAustria
| | | | - Bruno Di Geronimo
- Laboratory of Computer-Aided Molecular Design, Division of Medicinal Chemistry, Otto-Loewi Research Center, Medical University of GrazGrazAustria
| | - Gabriel E Wagner
- Institute of Chemistry / Organic and Bioorganic Chemistry, Medical University of GrazGrazAustria
- Diagnostic and Research Institute of Hygiene, Microbiology and Environmental Medicine, Medical University of GrazGrazAustria
| | | | | | - Markus Rotzinger
- Institute of Chemistry / Organic and Bioorganic Chemistry, Medical University of GrazGrazAustria
| | | | | | - Isabel Usón
- Institute of Molecular Biology of BarcelonaBarcelonaSpain
- ICREA, Institució Catalana de Recerca i Estudis AvançatsBarcelonaSpain
| | - Joachim Reidl
- Institute of Molecular Biosciences, University of GrazGrazAustria
- BioHealth Field of Excellence, University of GrazGrazAustria
- BioTechMed-GrazGrazAustria
| | - Pedro A Sánchez-Murcia
- Laboratory of Computer-Aided Molecular Design, Division of Medicinal Chemistry, Otto-Loewi Research Center, Medical University of GrazGrazAustria
| | - Klaus Zangger
- Institute of Chemistry / Organic and Bioorganic Chemistry, Medical University of GrazGrazAustria
- BioHealth Field of Excellence, University of GrazGrazAustria
- BioTechMed-GrazGrazAustria
| | - Tea Pavkov-Keller
- Institute of Molecular Biosciences, University of GrazGrazAustria
- BioHealth Field of Excellence, University of GrazGrazAustria
- BioTechMed-GrazGrazAustria
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Canals A, Pieretti S, Muriel-Masanes M, El Yaman N, Plecha SC, Thomson JJ, Fàbrega-Ferrer M, Pérez-Luque R, Krukonis ES, Coll M. ToxR activates the Vibrio cholerae virulence genes by tethering DNA to the membrane through versatile binding to multiple sites. Proc Natl Acad Sci U S A 2023; 120:e2304378120. [PMID: 37428913 PMCID: PMC10629549 DOI: 10.1073/pnas.2304378120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Accepted: 05/31/2023] [Indexed: 07/12/2023] Open
Abstract
ToxR, a Vibrio cholerae transmembrane one-component signal transduction factor, lies within a regulatory cascade that results in the expression of ToxT, toxin coregulated pilus, and cholera toxin. While ToxR has been extensively studied for its ability to activate or repress various genes in V. cholerae, here we present the crystal structures of the ToxR cytoplasmic domain bound to DNA at the toxT and ompU promoters. The structures confirm some predicted interactions, yet reveal other unexpected promoter interactions with implications for other potential regulatory roles for ToxR. We show that ToxR is a versatile virulence regulator that recognizes diverse and extensive, eukaryotic-like regulatory DNA sequences, that relies more on DNA structural elements than specific sequences for binding. Using this topological DNA recognition mechanism, ToxR can bind both in tandem and in a twofold inverted-repeat-driven manner. Its regulatory action is based on coordinated multiple binding to promoter regions near the transcription start site, which can remove the repressing H-NS proteins and prepares the DNA for optimal interaction with the RNA polymerase.
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Affiliation(s)
- Albert Canals
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, 08028Barcelona, Spain
- Institut de Biologia Molecular de Barcelona, Consejo Superior de Investigaciones Científicas, 08028Barcelona, Spain
| | - Simone Pieretti
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, 08028Barcelona, Spain
- Institut de Biologia Molecular de Barcelona, Consejo Superior de Investigaciones Científicas, 08028Barcelona, Spain
| | - Mireia Muriel-Masanes
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, 08028Barcelona, Spain
- Institut de Biologia Molecular de Barcelona, Consejo Superior de Investigaciones Científicas, 08028Barcelona, Spain
| | - Nour El Yaman
- Department of Biology, University of Detroit Mercy, Detroit, MI48221
| | - Sarah C. Plecha
- Division of Integrated Biomedical Sciences, University of Detroit Mercy School of Dentistry, Detroit, MI48208
| | - Joshua J. Thomson
- Division of Integrated Biomedical Sciences, University of Detroit Mercy School of Dentistry, Detroit, MI48208
| | - Montserrat Fàbrega-Ferrer
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, 08028Barcelona, Spain
- Institut de Biologia Molecular de Barcelona, Consejo Superior de Investigaciones Científicas, 08028Barcelona, Spain
| | - Rosa Pérez-Luque
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, 08028Barcelona, Spain
- Institut de Biologia Molecular de Barcelona, Consejo Superior de Investigaciones Científicas, 08028Barcelona, Spain
| | - Eric S. Krukonis
- Division of Integrated Biomedical Sciences, University of Detroit Mercy School of Dentistry, Detroit, MI48208
| | - Miquel Coll
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, 08028Barcelona, Spain
- Institut de Biologia Molecular de Barcelona, Consejo Superior de Investigaciones Científicas, 08028Barcelona, Spain
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Midgett CR, Kull FJ. Structural Insights into Regulation of Vibrio Virulence Gene Networks. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1404:269-294. [PMID: 36792881 DOI: 10.1007/978-3-031-22997-8_14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
One of the best studied aspects of pathogenic Vibrios are the virulence cascades that lead to the production of virulence factors and, ultimately, clinical outcomes. In this chapter, we will examine the regulation of Vibrio virulence gene networks from a structural and biochemical perspective. We will discuss the recent research into the numerous proteins that contribute to regulating virulence in Vibrio spp such as quorum sensing regulator HapR, the transcription factors AphA and AphB, or the virulence regulators ToxR and ToxT. We highlight how insights gained from these studies are already illuminating the basic molecular mechanisms by which the virulence cascade of pathogenic Vibrios unfold and contend that understanding how protein interactions contribute to the host-pathogen communications will enable the development of new antivirulence compounds that can effectively target these pathogens.
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Affiliation(s)
| | - F Jon Kull
- Chemistry Department, Dartmouth College, Hanover, NH, USA.
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Alviz-Gazitua P, González A, Lee MR, Aranda CP. Molecular Relationships in Biofilm Formation and the Biosynthesis of Exoproducts in Pseudoalteromonas spp. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2022; 24:431-447. [PMID: 35486299 DOI: 10.1007/s10126-022-10097-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 01/21/2022] [Indexed: 06/14/2023]
Abstract
Most members of the Pseudoalteromonas genus have been isolated from living surfaces as members of epiphytic and epizooic microbiomes on marine macroorganisms. Commonly Pseudoalteromonas isolates are reported as a source of bioactive exoproducts, i.e., secondary metabolites, such as exopolymeric substances and extracellular enzymes. The experimental conditions for the production of these agents are commonly associated with sessile metabolic states such as biofilms or liquid cultures in the stationary growth phase. Despite this, the molecular mechanisms that connect biofilm formation and the biosynthesis of exoproducts in Pseudoalteromonas isolates have rarely been mentioned in the literature. This review compiles empirical evidence about exoproduct biosynthesis conditions and molecular mechanisms that regulate sessile metabolic states in Pseudoalteromonas species, to provide a comprehensive perspective on the regulatory convergences that generate the recurrent coexistence of both phenomena in this bacterial genus. This synthesis aims to provide perspectives on the extent of this phenomenon for the optimization of bioprospection studies and biotechnology processes based on these bacteria.
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Affiliation(s)
- P Alviz-Gazitua
- Departamento de Ciencias Biológicas y Biodiversidad, Universidad de Los Lagos, Avda. Fuchslocher 1305, P. Box 5290000, Osorno, Chile
| | - A González
- Departamento de Ciencias Biológicas y Biodiversidad, Universidad de Los Lagos, Avda. Fuchslocher 1305, P. Box 5290000, Osorno, Chile
| | - M R Lee
- Centro i~mar, Universidad de Los Lagos, Camino a Chinquihue km 6, P. Box 5480000, Puerto Montt, Chile
| | - C P Aranda
- Departamento de Ciencias Biológicas y Biodiversidad, Universidad de Los Lagos, Avda. Fuchslocher 1305, P. Box 5290000, Osorno, Chile.
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