The Escherichia coli MarA protein regulates the ycgZ-ymgABC operon to inhibit biofilm formation
Research output: Contribution to journal › Article
- Institut für Biologie/Mikrobiologie, Humboldt-Universität zu Berlin, 10115, Berlin, Germany.
- Quadram Institute Bioscience, Norwich Research Park, Norwich, NR4 7UQ, UK.
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.
|Number of pages||17|
|Early online date||13 Sep 2019|
|Publication status||Published - Nov 2019|