ClbR Is the Key Transcriptional Activator of Colibactin Gene Expression in Escherichia coli.
Cast your vote
You can rate an item by clicking the amount of stars they wish to award to this item.
When enough users have cast their vote on this item, the average rating will also be shown.
Your vote was cast
Thank you for your feedback
Thank you for your feedback
Wami, Haleluya Tesfaye
von Bünau, Rudolf
MetadataShow full item record
AbstractColibactin is a nonribosomal peptide/polyketide hybrid natural product expressed by different members of the Enterobacteriaceae which can be correlated with induction of DNA double-strand breaks and interference with cell cycle progression in eukaryotes. Regulatory features of colibactin expression are only incompletely understood. We used Escherichia coli strain M1/5 as a model to investigate regulation of expression of the colibactin determinant at the transcriptional level and to characterize regulatory elements located within the colibactin pathogenicity island itself. We measured clbR transcription in vitro and observed that cultivation in defined minimal media led to increased colibactin expression relative to rich media. Transcription of clbR directly responds to iron availability. We also characterized structural DNA elements inside the colibactin determinant involved in ClbR-dependent regulation, i.e., ClbR binding sites and a variable number of tandem repeats located upstream of clbR We investigated the impact of clbR overexpression or deletion at the transcriptome and proteome levels. Moreover, we compared global gene regulation under these conditions with that occurring upon overexpression or deletion of clbQ, which affects the flux of colibactin production. Combining the results of the transcriptome and proteome analyses with indirect measurements of colibactin levels by cell culture assays and an approximate quantification of colibactin via the second product of colibactin cleavage from precolibactin, N-myristoyl-d-asparagine, we demonstrate that the variable number of tandem repeats plays a significant regulatory role in colibactin expression. We identify ClbR as the only transcriptional activator known so far that is specific and essential for efficient regulation of colibactin production.IMPORTANCE The nonribosomal peptide/polyketide hybrid colibactin can be considered a bacterial virulence factor involved in extraintestinal infection and also a procarcinogen. Nevertheless, and despite its genotoxic effect, colibactin expression can also inhibit bacterial or tumor growth and correlates with probiotic anti-inflammatory and analgesic properties. Although the biological function of this natural compound has been studied extensively, our understanding of the regulation of colibactin expression is still far from complete. We investigated in detail the role of regulatory elements involved in colibactin expression and in the growth conditions that promote colibactin expression. In this way, our data shed light on the regulatory mechanisms involved in colibactin expression and may support the expression and purification of this interesting nonribosomal peptide/polyketide hybrid for further molecular characterization.
CitationmSphere. 2020 Jul 29;5(4):]. mSphere. 2020;5(4):e00591-20. Published 2020 Jul 15. doi:10.1128/mSphere.00591-20.
AffiliationHIPS, Helmholtz-Institut für Pharmazeutische Forschung Saarland, Universitätscampus E8.1 66123 Saarbrücken, Germany.
The following license files are associated with this item:
- Creative Commons
Except where otherwise noted, this item's license is described as Attribution-NonCommercial-ShareAlike 4.0 International
- Expression analysis of the colibactin gene cluster coding for a novel polyketide in Escherichia coli.
- Authors: Homburg S, Oswald E, Hacker J, Dobrindt U
- Issue date: 2007 Oct
- The Colibactin Genotoxin Generates DNA Interstrand Cross-Links in Infected Cells.
- Authors: Bossuet-Greif N, Vignard J, Taieb F, Mirey G, Dubois D, Petit C, Oswald E, Nougayrède JP
- Issue date: 2018 Mar 20
- The Bacterial Stress-Responsive Hsp90 Chaperone (HtpG) Is Required for the Production of the Genotoxin Colibactin and the Siderophore Yersiniabactin in Escherichia coli.
- Authors: Garcie C, Tronnet S, Garénaux A, McCarthy AJ, Brachmann AO, Pénary M, Houle S, Nougayrède JP, Piel J, Taylor PW, Dozois CM, Genevaux P, Oswald E, Martin P
- Issue date: 2016 Sep 15
- Insights into evolution and coexistence of the colibactin- and yersiniabactin secondary metabolite determinants in enterobacterial populations.
- Authors: Wami H, Wallenstein A, Sauer D, Stoll M, von Bünau R, Oswald E, Müller R, Dobrindt U
- Issue date: 2021 Jun
- The Polyamine Spermidine Modulates the Production of the Bacterial Genotoxin Colibactin.
- Authors: Chagneau CV, Garcie C, Bossuet-Greif N, Tronnet S, Brachmann AO, Piel J, Nougayrède JP, Martin P, Oswald E
- Issue date: 2019 Oct 2