Mechanistic insights into transferable polymyxin resistance among gut bacteria
| Autor: | Youjun Feng, Yongchang Xu, Jingxia Lin, Tao Cui, Swaminath Srinivas |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
0301 basic medicine
medicine.drug_class Polymyxin 030106 microbiology Crystallography X-Ray Microbiology Biochemistry Lipid A 03 medical and health sciences Antibiotic resistance Drug Resistance Bacterial Escherichia coli medicine Polymyxins Molecular Biology Integral membrane protein Phylogeny biology Colistin Chemistry Escherichia coli Proteins Cell Biology biology.organism_classification Anti-Bacterial Agents Gastrointestinal Tract Molecular Docking Simulation Multiple drug resistance Ethanolamines Mutation Mutagenesis Site-Directed lipids (amino acids peptides and proteins) MCR-1 hormones hormone substitutes and hormone antagonists Bacteria medicine.drug |
| Zdroj: | Journal of Biological Chemistry. 293:4350-4365 |
| ISSN: | 0021-9258 |
| Popis: | Polymyxins such as colistin are antibiotics used as a final line of defense in the management of infections with multidrug-resistant Gram-negative bacteria. Although natural resistance to polymyxins is rare, the discovery of a mobilized colistin resistance gene (mcr-1) in gut bacteria has raised significant concern. As an intramembrane enzyme, MCR-1 catalyzes the transfer of phosphoethanolamine (PEA) to the 1 (or 4′)-phosphate group of the lipid A moiety of lipopolysaccharide, thereby conferring colistin resistance. However, the structural and biochemical mechanisms used by this integral membrane enzyme remain poorly understood. Here, we report the modeled structure of the full-length MCR-1 membrane protein. Together with molecular docking, our structural and functional dissection of the complex of MCR-1 with its phosphatidylethanolamine (PE) substrate suggested the presence of a 12 residue–containing cavity for substrate entry, which is critical for both enzymatic activity and its resultant phenotypic resistance to colistin. More importantly, two periplasm-facing helices (PH2 and PH2′) of the trans-membrane domain were essential for MCR-1 activity. MALDI-TOF MS and thin-layer chromatography assays provide both in vivo and in vitro evidence that MCR-1 catalyzes the transfer of PEA from the PE donor substrate to its recipient substrate lipid A. Also, the chemical modification of lipid A species was detected in clinical species of bacteria carrying mcr-1. Our results provide mechanistic insights into transferable MCR-1 polymyxin resistance, raising the prospect of rational design of small molecules that reverse bacterial polymyxin resistance, as a last-resort clinical option to combat pathogens with carbapenem resistance. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|