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Updated: Sep 11, 2025
06:30
A Non-Coding Small RNA MicC Contributes to Virulence in Outer Membrane Proteins in Salmonella Enteritidis
Published on: January 27, 2021
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The type 6 secretion system immunity protein RhsFI has been repurposed for small RNA regulation in pathogenic
Thomas Zammit1, Brandon Sy1, Vadim Shchepachev2
1School of Biotechnology and Biomolecular Sciences, UNSW, Sydney, 2033, Australia.
Nucleic Acids Research
|August 12, 2025
Summary
Pathogenic EHEC uses RNA-binding proteins like RhsFI to control virulence. RhsFI binds small RNAs, disrupting regulatory networks and promoting host colonization by altering gene expression.
Area of Science:
- Microbiology
- Molecular Biology
- Genetics
Background:
- Pathogenic enterohaemorrhagic Escherichia coli (EHEC) relies on RNA-binding proteins (RBPs) for virulence gene regulation.
- Understanding the full spectrum of RBPs in EHEC is crucial for deciphering its pathogenic mechanisms.
Purpose of the Study:
- To identify and characterize RNA-binding proteins in EHEC.
- To investigate the role of the type 6 secretion system (T6SS) immunity protein RhsFI in regulating gene expression and virulence.
Main Methods:
- Total RNA-associated protein purification (TRAPP) to identify RBPs.
- In vitro RNA-binding assays to confirm RBP activity.
- Deletion mutant analysis of the rhsF-rhsFI locus.
- Assessment of bacterial phenotypes including adhesion, morphology, and acid resistance.
Main Results:
- TRAPP identified 443 RNA-associated proteins, including RhsFI.
- RhsFI was confirmed to bind regulatory small RNAs (sRNAs) in vivo.
- Deletion of rhsF-rhsFI altered operon expression and significantly reduced bacterial adhesion to host cells.
- Loss of RhsFint-RhsFI impacted bacterial morphology and acid resistance.
Conclusions:
- The T6SS immunity protein RhsFI binds sRNAs in EHEC.
- RhsFI disrupts the sRNA regulatory network, impacting virulence.
- RhsFI plays a significant role in promoting EHEC host colonization.
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