FEMS microbiology letters, 2002-07, Vol.212 (2), p.249-254
2002
Details
- Autor(en) / Beteiligte
- Titel
- Efflux of chromate by Pseudomonas aeruginosa cells expressing the ChrA protein
- Ist Teil von
- FEMS microbiology letters, 2002-07, Vol.212 (2), p.249-254
- Ort / Verlag
- Oxford, UK: Blackwell Publishing Ltd
- Erscheinungsjahr
- 2002
- Link zum Volltext
- Quelle
- Wiley Online Library Journals Frontfile Complete
- Beschreibungen/Notizen
- Abstract The ChrA protein of Pseudomonas aeruginosa plasmid pUM505 confers resistance to chromate. Using an in vitro system, we reported [Alvarez, A.H. et al. (1999) J. Bacteriol. 181, 7398–7400] that chromate resistance is based on energy-dependent efflux of chromate. It is shown here that ChrA determines in vivo efflux of 51CrO42− as well. Chromate-loaded cell suspensions of P. aeruginosa strain PAO1 harboring recombinant plasmid pEPL1, which expresses the ChrA protein, showed accelerated efflux of 51CrO42− as compared to the plasmidless chromate-sensitive derivative. After a 10-min loading, about 40% of 51CrO42− was lost from resistant cells in 15 min. Chromate efflux by resistant cells showed a typical saturation kinetics with an apparent Km of 82±11 μM chromate and a Vmax of 0.133±0.009 nmol chromate min−1 (mg protein)−1. Oxyanions sulfate and molybdate inhibited chromate efflux in a concentration-dependent fashion, whereas arsenate and ortho-vanadate had no significant effect on chromate release. Inhibition of chromate extrusion by valinomycin, nigericin, and carbonyl cyanide m-chlorophenylhydrazone, but not by oligomycin or dicyclohexylcarbodiimide, indicated that chromate efflux was driven by the membrane potential.
- Sprache
- Englisch
- Identifikatoren
- ISSN: 0378-1097eISSN: 1574-6968DOI: 10.1111/j.1574-6968.2002.tb11274.xTitel-ID: cdi_proquest_miscellaneous_71895264
- Format
- –
- Schlagworte
- Anti-Bacterial Agents - pharmacology, Arsenates, Bacterial Proteins - genetics, Bacteriology, Biological and medical sciences, Biological Transport - drug effects, Biological Transport - physiology, Carbonyl compounds, Carbonyls, Cell suspensions, ChrA protein, Chromate, Chromate resistance, Chromates, Chromates - pharmacokinetics, Chromium Radioisotopes, Cyanide, Dicyclohexylcarbodiimide, Drug Resistance, Bacterial, Efflux, Energy Metabolism - drug effects, Extrusion, Fundamental and applied biological sciences. Psychology, Gene Expression Regulation, Bacterial, Genetics, In Vitro Techniques, In vivo methods and tests, Inhibition, Membrane potential, Membrane Proteins - genetics, Microbiology, Molybdate, Nigericin, Oligomycin, Oxides - metabolism, Plasmid, Plasmids, Proteins, Pseudomonas, Pseudomonas aeruginosa, Pseudomonas aeruginosa - drug effects, Pseudomonas aeruginosa - genetics, Pseudomonas aeruginosa - metabolism, Sulfates, Valinomycin, Vanadate