title: The energy-linked transhydrogenase reaction in respiratory mutants of Escherichia coli K12.
abstract: 1. Energy-linked and non-energy-linked transhydrogenase activities were assayed in membrane preparations from normal Escherichia coli K 12 and from various mutant strains. 2. The energy-linked transhydrogenase, which uses ATP as energy source, was dependent for activity on the presence of a functional Mg(2+)+Ca(2+)-stimulated adenosine triphosphatase. 3. Neither of the quinones formed by E. coli, namely ubiquinone-8 and menaquinone-8, was required for normal ATP-dependent energy-linked transhydrogenase activity. 4. The energy-linked transhydrogenase was inhibited by piericidin A at a site unrelated to the sites of inhibition of the electron-transport chain by piericidin A.
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D002118:Calcium; D004579:Electron Transport; D004926:Escherichia coli / Q000201:enzymology*; D008274:Magnesium; D009154:Mutation; D009243:NAD; D010088:Oxidoreductases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D011725:Pyridines / Q000494:pharmacology; D011809:Quinones; D014451:Ubiquinone
chemical_list: D011725:Pyridines; D011809:Quinones; D009243:NAD; D014451:Ubiquinone; D000255:Adenosine Triphosphate; D010088:Oxidoreductases; D000251:Adenosine Triphosphatases; D008274:Magnesium; D002118:Calcium