A synthetic lethal approach for compound and target identification in Staphylococcus aureus

Area of Science:

• Microbiology
• Drug Discovery
• Synthetic Biology

Background:

• Many bacterial proteins, though not essential for lab growth, play crucial physiological roles.
• Systematic methods for discovering cell-permeable small-molecule inhibitors of these proteins are lacking.
• Synthetic lethality offers a promising approach for both inhibitor discovery and target identification.

Purpose of the Study:

• To develop and apply a systematic strategy for identifying cell-permeable small-molecule inhibitors of essential bacterial proteins.
• To identify novel inhibitors targeting virulence factors in Staphylococcus aureus.
• To validate DltB as a druggable target within the bacterial D-alanylation pathway.

Main Methods:

• Exploited synthetic lethal relationships for small-molecule discovery and target identification.
• Applied the strategy to Staphylococcus aureus to identify inhibitors of the teichoic acid D-alanylation machinery.
• Investigated the effects of the identified inhibitor in combination with other antimicrobial agents.

Main Results:

• Identified a novel small-molecule inhibitor targeting DltB, a key component of the teichoic acid D-alanylation pathway.
• The DltB inhibitor demonstrated synergistic effects, sensitizing S. aureus to aminoglycosides and cationic peptides.
• The inhibitor was found to be lethal when combined with a wall teichoic acid inhibitor, highlighting DltB's druggability.

Conclusions:

• DltB is a validated druggable target in the bacterial D-alanylation pathway, offering a potential therapeutic strategy.
• The developed systematic method is broadly applicable for identifying inhibitors of major bacterial processes across diverse organisms.
• This approach advances the discovery of novel antimicrobials by targeting proteins with important physiological roles beyond basic growth.