BacPROTACs mediate targeted protein degradation in bacteria

Area of Science:

• Bacterial protein degradation
• Drug discovery
• Molecular biology

Background:

• Targeting bacterial protein degradation is a promising strategy for drug discovery.
• Existing proteolysis-targeting chimeras (PROTACs) are effective in eukaryotes but not bacteria.
• The bacterial ClpC:ClpP protease system is a potential target for antimicrobial intervention.

Purpose of the Study:

• To develop bacterial proteolysis-targeting chimeras (BacPROTACs) for targeted protein degradation in bacteria.
• To investigate the mechanism of BacPROTACs in activating the ClpC:ClpP protease.
• To demonstrate the in vivo efficacy of BacPROTACs in mycobacteria for antibiotic discovery.

Main Methods:

• Design and synthesis of small-molecule BacPROTACs targeting the ClpC:ClpP protease.
• Cryo-electron microscopy (cryo-EM) to visualize the activated ClpC protease.
• Drug susceptibility and protein degradation assays in mycobacteria.

Main Results:

• BacPROTACs bind to the ClpC:ClpP protease substrate receptor, priming neo-substrates for degradation.
• BacPROTACs activate ClpC, converting it from a resting unfoldase to a functional state.
• Cryo-EM revealed the structural basis of ClpC activation and substrate unfolding.
• In vivo assays in mycobacteria confirmed BacPROTACs' ability to selectively degrade endogenous proteins.

Conclusions:

• BacPROTAC technology enables targeted degradation of bacterial proteins by hijacking the ClpC:ClpP system.
• This approach provides a versatile tool for antibiotic discovery and fundamental research in bacterial biology.
• BacPROTACs represent a significant advancement in reprogramming bacterial degradation machinery for therapeutic purposes.