An Optimized Workflow for the Discovery of New Antimicrobial Compounds Targeting Bacterial RNA Polymerase Complex...

Area of Science:

• Microbiology
• Drug Discovery
• Biochemistry

Background:

• Bacterial resistance is a global health crisis requiring novel antimicrobial agents.
• Targeting essential bacterial processes like transcription is a promising strategy.
• Disrupting the interaction between the RNA polymerase β' subunit and the σ⁷⁰ factor is a validated antimicrobial target.

Purpose of the Study:

• To optimize a drug discovery platform for identifying inhibitors of the bacterial RNA polymerase β'-σ⁷⁰ interaction.
• To discover novel, first-in-class compounds with antibacterial activity.
• To improve the cost-effectiveness and speed of antimicrobial drug discovery.

Main Methods:

• Development of a three-step, high-throughput screening assay workflow.
• Screening of 5,360 small molecules from diverse compound libraries.
• Characterization of hit compounds for their ability to inhibit transcription and bacterial growth.

Main Results:

• Identification of six compounds that interfere with the β'-σ⁷⁰ protein-protein interaction.
• Demonstration that these compounds inhibit promoter-specific RNA transcription and bacterial growth.
• Two potent compounds showed significant antibacterial activity against *Escherichia coli* (MIC 0.87-1.56 μM) when supplemented with a permeability adjuvant.
• The identified compounds align with a previously established pharmacophore model for β'-σ⁷⁰ PPI inhibitors.

Conclusions:

• The optimized screening platform is efficient and cost-effective for identifying novel antimicrobial drug candidates.
• The identified compounds represent promising leads for developing new antibiotics targeting bacterial transcription.
• This work validates the β'-σ⁷⁰ interaction as a viable target for novel antibacterial agents.