Making and Breaking Leupeptin Protease Inhibitors in Pathogenic Gammaproteobacteria
- Angew Chem Int Ed Engl. 2020 Oct 5;59(41):17872-17880. doi: 10.1002/anie.202005506.
- 1. Department of Chemistry, Yale University, New Haven, CT, 06520, USA.
- 2. Chemical Biology Institute, Yale University, West Haven, CT, 06516, USA.
- 3. Institute of Molecular Biosciences, University of Graz, 8010, Graz, Austria.
- 4. School of Microbiology and APC Microbiome Ireland, University College Cork, Cork, Ireland.
- 5. BioTechMed-Graz, 8010, Graz, Austria.
- 6. Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT, 06536, USA.
Leupeptin is a Bacterial small molecule that is used worldwide as a protease inhibitor. However, its biosynthesis and genetic distribution remain unknown. We identified a family of leupeptins in gammaproteobacterial pathogens, including Photorhabdus, Xenorhabdus, and Klebsiella species, amongst Others. Through genetic, metabolomic, and heterologous expression analyses, we established their construction by discretely expressed ligases and accessory Enzymes. In Photorhabdus species, a hypothetical protein required for colonizing nematode hosts was established as a new class of proteases. This enzyme cleaved the tripeptide aldehyde Protease Inhibitors, leading to the formation of "pro-pyrazinones" featuring a hetero-tricyclic architecture. In Klebsiella oxytoca, the pathway was enriched in clinical isolates associated with respiratory tract infections. Thus, the Bacterial production and proteolytic degradation of leupeptins can be associated with animal colonization phenotypes.