Abstract |
Regulation of synthesis of cytochrome d in Escherichia coli has been studied using mutants with cytochrome-d-- beta-galactosidase gene fusions. It was shown that various protonophorous uncouplers, when added to the growth medium, cause induction of the cytochrome d synthesis. The cytochrome-d-inducing activity of uncouplers correlates with their ability to inhibit such a delta mu (H+)-driven function as motility of the E. coli cells. An increase in the Na+ concentration in the growth medium from 1.5 mM to 25 mM results in induction of the cytochrome d synthesis. The cytochrome-d-inducing effect of uncouplers is much more pronounced when the Na+ concentration is high than when it is low. These data are in agreement with the assumption that cytochrome d is involved in the Na+ energetics substituting for the H+ energetics when the latter appears to be inefficient. Mutations in arcA or arcB genes (but not in fnr gene) completely prevent the increase in the cytochrome d level induced by uncouplers but are without effect on that induced by Na+. It is assumed that in the control of the cytochrome d synthesis, the Arc system is involved in the delta mu H+ sensing whereas sensing of delta mu Na+ (or of the Na+ concentration) is mediated by some other receptor system.
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Authors | A V Bogachev, R A Murtazine, A I Shestopalov, V P Skulachev |
Journal | European journal of biochemistry
(Eur J Biochem)
Vol. 232
Issue 1
Pg. 304-8
(Aug 15 1995)
ISSN: 0014-2956 [Print] England |
PMID | 7556165
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- Ions
- Recombinant Fusion Proteins
- Hydrogen
- Cytochrome d Group
- Sodium
- beta-Galactosidase
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Topics |
- Cytochrome d Group
(biosynthesis, genetics)
- Enzyme Induction
- Escherichia coli
(enzymology)
- Hydrogen
(pharmacology)
- Ions
- Mutation
- Recombinant Fusion Proteins
(biosynthesis, genetics)
- Sodium
(pharmacology)
- beta-Galactosidase
(biosynthesis, genetics)
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