Functional Characterisation of ClpP Mutations Conferring Resistance to Acyldepsipeptide Antibiotics in Firmicutes

Chembiochem. 2020 Jul 16;21(14):1997-2012. doi: 10.1002/cbic.201900787. Epub 2020 Apr 9.


Acyldepsipeptide (ADEP) is an exploratory antibiotic with a novel mechanism of action. ClpP, the proteolytic core of the caseinolytic protease, is deregulated towards unrestrained proteolysis. Here, we report on the mechanism of ADEP resistance in Firmicutes. This bacterial phylum contains important pathogens that are relevant for potential ADEP therapy. For Staphylococcus aureus, Bacillus subtilis, enterococci and streptococci, spontaneous ADEP-resistant mutants were selected in vitro at a rate of 10-6 . All isolates carried mutations in clpP. All mutated S. aureus ClpP proteins characterised in this study were functionally impaired; this increased our understanding of the mode of operation of ClpP. For molecular insights, crystal structures of S. aureus ClpP bound to ADEP4 were determined. Well-resolved N-terminal domains in the apo structure allow the pore-gating mechanism to be followed. The compilation of mutations presented here indicates residues relevant for ClpP function and suggests that ADEP resistance will occur at a lower rate during the infection process.

Keywords: ADEP; ClpP; acyldepsipepide; antibiotics; natural products; protease.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Bacterial Agents / chemistry
  • Anti-Bacterial Agents / pharmacology*
  • Depsipeptides / chemistry
  • Depsipeptides / pharmacology*
  • Drug Resistance, Bacterial / drug effects*
  • Endopeptidase Clp / antagonists & inhibitors*
  • Endopeptidase Clp / metabolism
  • Firmicutes / drug effects*
  • Firmicutes / enzymology
  • Microbial Sensitivity Tests
  • Molecular Conformation
  • Mutation
  • Staphylococcus aureus / drug effects*
  • Staphylococcus aureus / enzymology


  • Anti-Bacterial Agents
  • Depsipeptides
  • Endopeptidase Clp