Mutation in Elongation Factor G Confers Resistance to the Antibiotic Argyrin in the Opportunistic Pathogen Pseudomonas aeruginosa |
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Authors: | Dr Piotr Bielecki Dr Peer Lukat Kristina Hüsecken Dr Andreas Dötsch Heinrich Steinmetz Prof Dr Rolf W Hartmann Prof Dr Rolf Müller Prof Dr Susanne Häussler |
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Affiliation: | 1. Department of Molecular Bacteriology, Helmholtz Center for Infection Research, Inhoffenstrasse 7, 38124 Braunschweig (Germany);2. Institute of Molecular Bacteriology, Twincore, Center for Clinical and Experimental Infection Research, A joint venture of the Helmholtz Center of Infection Research and the Hannover Medical School, Feodor‐Lynen Strasse 7, 30265 Hannover (Germany);3. Helmholtz Institute for Pharmaceutical Research Saarland, Helmholtz Center for Infection Research and Pharmaceutical Biotechnology, Saarland University, 66123 Saarbrücken (Germany);4. Department of Molecular Structural Biology, Helmholtz Center for Infection Research, 38124 Braunschweig (Germany);5. Department of Microbial Drugs, Helmholtz Center for Infection Research, 38124 Braunschweig (Germany) |
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Abstract: | The natural myxobacterial product argyrin is a cyclic peptide exhibiting immunosuppressive activity as well as antibacterial activity directed against the highly intrinsically resistant opportunistic pathogen Pseudomonas aeruginosa. In this study, we used whole‐genome sequencing technology as a powerful tool to determine the mode of action of argyrin. Sequencing of argyrin‐resistant P. aeruginosa isolates selected in vitro uncovered six point mutations that distinguished the resistant mutants from their susceptible parental strain. All six mutations were localized within one gene: fusA1, which encodes for the elongation factor EF‐G. After the reintroduction of selected mutations into the susceptible wild type, the strain became resistant to argyrin. Surface plasmon resonance experiments confirmed the interaction of argyrin A with FusA1. Interestingly, EF‐G has been previously shown to be the target of the anti‐Staphylococcus antibiotic fusidic acid. Mapping of the mutations onto a structural model of EF‐G revealed that the mutations conveying resistance against argyrin were clustered within domain III on the side opposite to that involved in fusidic acid binding, thus indicating that argyrin exhibits a new mode of protein synthesis inhibition. Although no mutations causing argyrin resistance have been found in other genes of P. aeruginosa, analysis of the sequence identity in EF‐G and its correlation with argyrin resistance in different bacteria imply that additional factors such as uptake of argyrin play a role in the argyrin resistance of other organisms. |
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Keywords: | antibiotics natural products resistance target identification whole‐genome sequencing |
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