Generation of a membrane potential by one of two independent pathways for nitrite reduction by Escherichia coli.
A set of four isogenic Escherichia coli strains has been constructed in which all possible combinations of NADH- and formate-dependent nitrite reductases are active or inactive. Each pathway can be inactivated genetically without a corresponding loss in the other activity: the two pathways are therefore biochemically independent. The generation of a membrane potential during nitrite reduction by formate has been demonstrated using an ion-selective electrode specific for a lipophilic cation. The observed energy conservation results, at least in part, from the ability of formate dehydrogenase in E. coli to pump protons.
D004734:Energy Metabolism; D004926:Escherichia coli / Q000378:metabolism*; D005560:Formate Dehydrogenases / Q000378:metabolism; D007473:Ion Channels; D008564:Membrane Potentials; D009247:NADH, NADPH Oxidoreductases / Q000378:metabolism; D009565:Nitrate Reductases / Q000378:metabolism*; D011522:Protons
D007473:Ion Channels; D011522:Protons; D005560:Formate Dehydrogenases; D009247:NADH, NADPH Oxidoreductases; D009565:Nitrate Reductases