| Literature DB >> 7934881 |
J J Rowe1, T Ubbink-Kok, D Molenaar, W N Konings, A J Driessen.
Abstract
Escherichia coli can use nitrate as a terminal electron acceptor for anaerobic respiration. A polytopic membrane protein, termed NarK, has been implicated in nitrate uptake and nitrite excretion and is thought to function as a nitrate/nitrite antiporter. The longest-lived radioactive isotope of nitrogen, 13N-nitrate (half-life = 9.96 min) and the nitrite-sensitive fluorophore N-(ethoxycarbonylmethyl)-6-methoxyquinolinium bromide have now been used to define the function of NarK. At low concentrations of nitrate, NarK mediates the electrogenic excretion of nitrite rather than nitrate/nitrite exchange. This process prevents intracellular accumulation of toxic levels of nitrite and allows further detoxification in the periplasm through the action of nitrite reductase.Entities:
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Year: 1994 PMID： 7934881 DOI： 10.1111/j.1365-2958.1994.tb01044.x
Source DB: PubMed Journal: Mol Microbiol ISSN： 0950-382X Impact factor: 3.501