The Escherichia coli MarA protein regulates the ycgZ-ymgABC operon to inhibit biofilm formation

Kettles, Rachel A., Tschowri, Natalia, Lyons, Kevin J., Sharma, Prateek, Hengge, Regine, Webber, Mark A. and Grainger, David C. (2019) The Escherichia coli MarA protein regulates the ycgZ-ymgABC operon to inhibit biofilm formation. Molecular Microbiology, 112 (5). pp. 1609-1625. ISSN 0950-382X

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The Escherichia coli marRAB operon is a paradigm for chromosomally encoded antibiotic resistance. The operon exerts its effect via an encoded transcription factor called MarA that modulates efflux pump and porin expression. In this work, we show that MarA is also a regulator of biofilm formation. Control is mediated by binding of MarA to the intergenic region upstream of the ycgZ-ymgABC operon. The operon, known to influence the formation of curli fibres and colanic acid, is usually expressed during periods of starvation. Hence, the ycgZ-ymgABC promoter is recognised by σ38 (RpoS)-associated RNA polymerase (RNAP). Surprisingly, MarA does not influence σ38 -dependent transcription. Instead, MarA drives transcription by the housekeeping σ70 -associated RNAP. The effects of MarA on ycgZ-ymgABC expression are coupled with biofilm formation by the rcsCDB phosphorelay system, with YcgZ, YmgA and YmgB forming a complex that directly interacts with the histidine kinase domain of RcsC.

Item Type: Article
Additional Information: © 2019 The Authors. Molecular Microbiology published by John Wiley & Sons Ltd.
Faculty \ School: Faculty of Medicine and Health Sciences > Norwich Medical School
Depositing User: LivePure Connector
Date Deposited: 29 Feb 2020 08:35
Last Modified: 22 Oct 2022 05:53
DOI: 10.1111/mmi.14386


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