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ATP‐driven Na + transport and Na + ‐dependent ATP synthesis in Escherichia coli grown at low \Δgm H +
Author(s) -
Avetisyan A.V.,
Bogachev A.V.,
Murtasina R.A.,
Skulachev V.P.
Publication year - 1993
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(93)81290-g
Subject(s) - protonophore , antiporter , oxidative phosphorylation , monensin , escherichia coli , atpase , atp synthase , chemistry , nigericin , ion transporter , phosphorylation , vesicle , electrochemical gradient , membrane transport , biochemistry , biophysics , membrane potential , biology , membrane , enzyme , gene
In inverted subcellular vesicles of Escherichia coli grown at high \Δgm H + (neutral pH, no protonophorous uncoupler), ATP‐driven Na + transport and oxidative phosphorylation are completely inhibited by the protonophore CCCP. If E coli was grown at low \Δgm H + , i.e. at high pH or in the presence of uncoupler, some oxidative phosphorylation was observed in the vesicles even in CCCP‐containing medium, and Na + transport was actually stimulated by CCCP. The CCCP‐resistant transport and phosphorylation were absent from the unc mutant lacking F 0 F 1 , ATPase. Both processes proved to be sensitive to (i) the Na + /H + antiporter monensin, (ii) the Na + uniporter ETH 157, (iii) the F 0 inhibitors DCCD and venturicidin, and (iv) the F 1 inhibitor aurovertin. The CCCP‐resistant oxidative phosphorylation was stimulated by Na + and arrested by oppositely directed ΔpNa. These data are consistent with the assumption that, under appropriate growth conditions, the F 0 F 1 ‐type ATPase of E. coli becomes competent in transporting Na + ions.