Design and characterization of Escherichia coli mutants devoid of Ap4N-hydrolase activity
| Autor: | Françoise Lévq̂ue, Sylvie Blanchin-Roland, Sylvain Blanquet, Pierre Plateau, Guy Fayat |
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| Rok vydání: | 1990 |
| Předmět: |
Operon
Restriction Mapping Mutant Kasugamycin medicine.disease_cause 03 medical and health sciences chemistry.chemical_compound Plasmid Structural Biology Escherichia coli medicine Cloning Molecular Molecular Biology 030304 developmental biology 0303 health sciences biology Phosphoric Diester Hydrolases 030306 microbiology Temperature Drug Resistance Microbial biology.organism_classification Enterobacteriaceae Molecular biology Acid Anhydride Hydrolases Anti-Bacterial Agents Complementation Blotting Southern Aminoglycosides Phenotype chemistry Genes Bacterial Mutation Growth inhibition Plasmids |
| Zdroj: | Journal of Molecular Biology. 212:319-329 |
| ISSN: | 0022-2836 |
| Popis: | Escherichia coli strains with abnormally high concentrations of bis(5'-nucleosidyl)-tetraphosphates (Ap4N) were constructed by disrupting the apaH gene that encodes Ap4N-hydrolase. Variation deletions and insertions were also introduced in apaG and ksgA, two other cistrons of the ksgA apaGH operon. In all strains studied, a correlation was found between the residual Ap4N-hydrolase activity and the intracellular Ap4N concentration. In cells that do not express apaH at all, the Ap4N concentration was about 100-fold higher than in the parental strain. Such a high Ap4N level did not modify the bacterial growth rate in rich or minimal medium. However, while, as expected, the ksgA- and apaG- ksgA- strains stopped growing in the presence of this antibiotic at 600 micrograms/ml. The were not sensitive to kasugamycin, the apaH- apaG- ksgA- strain filamented and stopped growing in the presence of this antibiotic at 600 micrograms/ml. The growth inhibition was abolished upon complementation with a plasmid carrying an intact apaH gene. Trans addition of extra copies of the heat-shock gene dnaK also prevented the kasugamycin-induced filamentation of apaH- apaG- ksgA- strains. This result is discussed in relation to the possible involvement of Ap4N in cellular adaptation following a stress. |
| Databáze: | OpenAIRE |
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