A Disulfide Constrains the ToxR Periplasmic Domain Structure, Altering Its Interactions with ToxS and Bile-salts

Overview

Journal Sci Rep

Specialty Science

Date 2020 Jun 4

PMID 32488093

Citations 7

Authors

Charles R Midgett

Rachel A Swindell

Maria Pellegrini

F Jon Kull

Affiliations

Soon will be listed here.

Abstract

ToxR is a transmembrane transcription factor that, together with its integral membrane periplasmic binding partner ToxS, is conserved across the Vibrionaceae family. In some pathogenic Vibrios, including V. parahaemolyticus and V. cholerae, ToxR is required for bile resistance and virulence, and ToxR is fully activated and protected from degradation by ToxS. ToxS achieves this in part by ensuring formation of an intra-chain disulfide bond in the C-terminal periplasmic domain of ToxR (dbToxRp). In this study, biochemical analysis showed dbToxRp to have a higher affinity for the ToxS periplasmic domain than the non-disulfide bonded conformation. Analysis of our dbToxRp crystal structure showed this is due to disulfide bond stabilization. Furthermore, dbToxRp is structurally homologous to the V. parahaemolyticus VtrA periplasmic domain. These results highlight the critical structural role of disulfide bond in ToxR and along with VtrA define a domain fold involved in environmental sensing conserved across the Vibrionaceae family.

Citing Articles

CsrA controls ToxR levels by increasing the stability and translation of mRNA.

Mey A, Midgett C, Kull F, Payne S mBio. 2024; 15(12):e0285324.

PMID: 39555915 PMC: 11633198. DOI: 10.1128/mbio.02853-24.

An essential host dietary fatty acid promotes TcpH inhibition of TcpP proteolysis promoting virulence gene expression in .

Demey L, Sinha R, DiRita V mBio. 2024; 15(8):e0072124.

PMID: 38958446 PMC: 11323476. DOI: 10.1128/mbio.00721-24.

ToxR activates the virulence genes by tethering DNA to the membrane through versatile binding to multiple sites.

Canals A, Pieretti S, Muriel-Masanes M, El Yaman N, Plecha S, Thomson J Proc Natl Acad Sci U S A. 2023; 120(29):e2304378120.

PMID: 37428913 PMC: 10629549. DOI: 10.1073/pnas.2304378120.

Structural Insights into Regulation of Vibrio Virulence Gene Networks.

Midgett C, Kull F Adv Exp Med Biol. 2023; 1404:269-294.

PMID: 36792881 DOI: 10.1007/978-3-031-22997-8_14.

Co-component signal transduction systems: Fast-evolving virulence regulation cassettes discovered in enteric bacteria.

Kinch L, Cong Q, Jaishankar J, Orth K Proc Natl Acad Sci U S A. 2022; 119(24):e2203176119.

PMID: 35648808 PMC: 9214523. DOI: 10.1073/pnas.2203176119.

References

Hase C, Mekalanos J . TcpP protein is a positive regulator of virulence gene expression in Vibrio cholerae. Proc Natl Acad Sci U S A. 1998; 95(2):730-4. PMC: 18489. DOI: 10.1073/pnas.95.2.730. View

Miller V, Mekalanos J . Synthesis of cholera toxin is positively regulated at the transcriptional level by toxR. Proc Natl Acad Sci U S A. 1984; 81(11):3471-5. PMC: 345530. DOI: 10.1073/pnas.81.11.3471. View

Miller V, DiRita V, Mekalanos J . Identification of toxS, a regulatory gene whose product enhances toxR-mediated activation of the cholera toxin promoter. J Bacteriol. 1989; 171(3):1288-93. PMC: 209743. DOI: 10.1128/jb.171.3.1288-1293.1989. View

Wang S, Lauritz J, Jass J, Milton D . A ToxR homolog from Vibrio anguillarum serotype O1 regulates its own production, bile resistance, and biofilm formation. J Bacteriol. 2002; 184(6):1630-9. PMC: 134897. DOI: 10.1128/JB.184.6.1630-1639.2002. View

Cremers C, Knoefler D, Vitvitsky V, Banerjee R, Jakob U . Bile salts act as effective protein-unfolding agents and instigators of disulfide stress in vivo. Proc Natl Acad Sci U S A. 2014; 111(16):E1610-9. PMC: 4000791. DOI: 10.1073/pnas.1401941111. View

Lembke M, Pennetzdorfer N, Tutz S, Koller M, Vorkapic D, Zhu J . Proteolysis of ToxR is controlled by cysteine-thiol redox state and bile salts in Vibrio cholerae. Mol Microbiol. 2018; 110(5):796-810. PMC: 6242745. DOI: 10.1111/mmi.14125. View

Provenzano D, Schuhmacher D, Barker J, Klose K . The virulence regulatory protein ToxR mediates enhanced bile resistance in Vibrio cholerae and other pathogenic Vibrio species. Infect Immun. 2000; 68(3):1491-7. PMC: 97306. DOI: 10.1128/IAI.68.3.1491-1497.2000. View

Midgett C, Almagro-Moreno S, Pellegrini M, Taylor R, Skorupski K, Kull F . Bile salts and alkaline pH reciprocally modulate the interaction between the periplasmic domains of Vibrio cholerae ToxR and ToxS. Mol Microbiol. 2017; 105(2):258-272. PMC: 5498992. DOI: 10.1111/mmi.13699. View

Adams P, Afonine P, Bunkoczi G, Chen V, Davis I, Echols N . PHENIX: a comprehensive Python-based system for macromolecular structure solution. Acta Crystallogr D Biol Crystallogr. 2010; 66(Pt 2):213-21. PMC: 2815670. DOI: 10.1107/S0907444909052925. View

10.

Kabsch W . XDS. Acta Crystallogr D Biol Crystallogr. 2010; 66(Pt 2):125-32. PMC: 2815665. DOI: 10.1107/S0907444909047337. View

11.

Bina J, Zhu J, Dziejman M, Faruque S, Calderwood S, Mekalanos J . ToxR regulon of Vibrio cholerae and its expression in vibrios shed by cholera patients. Proc Natl Acad Sci U S A. 2003; 100(5):2801-6. PMC: 151421. DOI: 10.1073/pnas.2628026100. View

12.

Dziejman M, Kolmar H, Fritz H, Mekalanos J . ToxR co-operative interactions are not modulated by environmental conditions or periplasmic domain conformation. Mol Microbiol. 1999; 31(1):305-17. DOI: 10.1046/j.1365-2958.1999.01173.x. View

13.

Almagro-Moreno S, Root M, Taylor R . Role of ToxS in the proteolytic cascade of virulence regulator ToxR in Vibrio cholerae. Mol Microbiol. 2015; 98(5):963-76. DOI: 10.1111/mmi.13170. View

14.

Yang Y, Isberg R . Transcriptional regulation of the Yersinia pseudotuberculosis pH6 antigen adhesin by two envelope-associated components. Mol Microbiol. 1997; 24(3):499-510. DOI: 10.1046/j.1365-2958.1997.3511719.x. View

15.

Fan F, Liu Z, Jabeen N, Birdwell L, Zhu J, Kan B . Enhanced interaction of Vibrio cholerae virulence regulators TcpP and ToxR under oxygen-limiting conditions. Infect Immun. 2014; 82(4):1676-82. PMC: 3993381. DOI: 10.1128/IAI.01377-13. View

16.

Holm L, Laakso L . Dali server update. Nucleic Acids Res. 2016; 44(W1):W351-5. PMC: 4987910. DOI: 10.1093/nar/gkw357. View

17.

Pettersen E, Goddard T, Huang C, Couch G, Greenblatt D, Meng E . UCSF Chimera--a visualization system for exploratory research and analysis. J Comput Chem. 2004; 25(13):1605-12. DOI: 10.1002/jcc.20084. View

18.

Kodama T, Gotoh K, Hiyoshi H, Morita M, Izutsu K, Akeda Y . Two regulators of Vibrio parahaemolyticus play important roles in enterotoxicity by controlling the expression of genes in the Vp-PAI region. PLoS One. 2010; 5(1):e8678. PMC: 2800187. DOI: 10.1371/journal.pone.0008678. View

19.

Champion G, Neely M, Brennan M, DiRita V . A branch in the ToxR regulatory cascade of Vibrio cholerae revealed by characterization of toxT mutant strains. Mol Microbiol. 1997; 23(2):323-31. DOI: 10.1046/j.1365-2958.1997.2191585.x. View

20.

Ottemann K, Mekalanos J . Analysis of Vibrio cholerae ToxR function by construction of novel fusion proteins. Mol Microbiol. 1995; 15(4):719-31. DOI: 10.1111/j.1365-2958.1995.tb02380.x. View