Developing a Novel Antibiotic: Isolating Inhibitors of SigmaE and Hfq Using a Cell-Based High-Throughput Assay

Open Access
Author:
Brezovec, Luke Edward
Area of Honors:
Biochemistry and Molecular Biology
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
  • Sarah Ellen Ades, Thesis Supervisor
  • Teh Hui Kao, Honors Advisor
Keywords:
  • antibiotic
  • SigmaE
  • Hfq
Abstract:
The emergence and spread of antibiotic resistance throughout a wide range of bacterial pathogens is causing a serious global health crisis – there is high demand for new antibiotics effective against these resistant pathogens. Here, a cell-based high-throughput assay is developed and utilized to identify inhibitors of SigmaE and Hfq. SigmaE is an alternative transcription factor that mediates the SigmaE envelope stress response, which senses damage to the cell envelope and directs expression of genes important in combating envelope stress. The pathway is critical for the virulence or viability of many bacterial pathogens, making it a good candidate for a target-based screen to identify novel antibiotics. Hfq facilitates the pairing of sRNAs with their cognate mRNAs and plays a key role in the SigmaE pathway, as well as many other bacterial pathways important for virulence. SigmaE inhibitors isolated from this assay are shown to kill E. coli, and Hfq inhibitors are biochemically shown to inhibit Hfq binding to RNA in-vitro. Beside their potential as future antibiotics, inhibitors will be useful tools to probe and study the fundamental biology of SigmaE and Hfq.