| Affiliation: | 1. Interfaculty Institute of Microbiology and Infection Medicine, Dept. of Microbial Bioactive Compounds, University of Tübingen, Auf der Morgenstelle 28, 72076 Tuebingen, Germany;2. Interfaculty Institute of Microbiology and Infection Medicine, Dept. of Microbial Bioactive Compounds, University of Tübingen, Auf der Morgenstelle 28, 72076 Tuebingen, Germany
Laboratory of Antibiotics, Biochemistry, Education and Molecular modeling, Department of Molecular and Cell Biology, Federal Fluminense University, Outeiro São João Batista, Centro, Niterói, 24210130 Rio de Janeiro, Brazil;3. Center for Integrated Protein Science at the Department of Chemistry, Technical University Munich, Lichtenbergstrasse 4, 85748 Garching, Germany;4. Institute for Pharmaceutical Biology and Biotechnology, University of Düsseldorf, Universitätsstrasse 1, Building 26.23., 40225 Düsseldorf, Germany;5. Laboratory of Antibiotics, Biochemistry, Education and Molecular modeling, Department of Molecular and Cell Biology, Federal Fluminense University, Outeiro São João Batista, Centro, Niterói, 24210130 Rio de Janeiro, Brazil |
| Abstract: | 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. |
