Mechanisms of glycopeptide resistance in enterococci
| Autor: | Patrice Courvalin, S. Evers, Richard Quintiliani, Sylvie Dutka-Malen, Florence Depardieu, Peter E. Reynolds, Michel Arthur |
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| Rok vydání: | 1996 |
| Předmět: |
Microbiology (medical)
chemistry.chemical_classification Depsipeptide Transposable element DNA ligase Dipeptide Dehydrogenase Drug Resistance Microbial Biology biology.organism_classification Glycopeptide Anti-Bacterial Agents carbohydrates (lipids) chemistry.chemical_compound Infectious Diseases chemistry Biochemistry Vancomycin DNA Transposable Elements bacteria Peptidoglycan Amino Acid Sequence Bacteria Enterococcus |
| Zdroj: | The Journal of infection. 32(1) |
| ISSN: | 0163-4453 |
| Popis: | Inducible resistance to high levels of glycopeptide antibiotics in clinical isolates of enterococci is mediated by Tn1546 or related transposons. Tn1546 encodes the VanH dehydrogenase which reduces pyruvate to D-lactate (D-Lac) and the VanA ligase which catalyses synthesis of the depsipeptide D-alanyl-D-lactate (D-Ala-D-Lac). The depsipeptide replaces the dipeptide D-Ala-D-Ala leading to production of peptidoglycan precursors which bind glycopeptides with reduced affinity. In addition, Tn1546 encodes the VanX dipeptidase and the VanY D,D-carboxypeptidase that hydrolyse the dipeptide D-Ala-D-Ala and the C-terminal D-Ala residue of the cytoplasmic precursor UDP-MurNAC-L-Ala-gamma-D- Glu-L-Lys-D-Ala-D-Ala, respectively. These two proteins act in series to eliminate D-Ala-D-Ala-containing precursors. VanX is required for resistance whereas VanY only slightly increases the level of resistance mediated by VanH, VanA and VanX. |
| Databáze: | OpenAIRE |
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