Formation of an ion transport supercomplex in Escherichia coli. An experimental model of direct transduction of energy.
Hydrogen gas production was observed to occur during ATP-driven H+/K+ exchange in anaerobically grown E. coli. Neither process was found in aerobically grown cells or anaerobic cells grown on nitrate medium or when the osmotic pressure was decreased or K+ removed, or finally when DCCD, arsenate or CCCP was applied. Dithiothreitol restored the process even in the presence of CCCP but not in other cases of inhibition. A model of a multienzyme transport super-complex is proposed. The supercomplex consists of three genetically independent mechanisms: F0F1 H+-ATPase to provide energy, the K+-transporting Trk system as energy sink and formate-hydrogen lyase as donor of reducing equivalents. Within this supercomplex direct transduction of energy is accomplished via oxidation of 2 SH to S-S.
Bagramyan
K A
KA
Orbeli Institute of Physiology, Armenian Academy of Sciences, Yerevan, USSR.
Martirosov
S M
SM
D000445:Aldehyde Oxidoreductases / Q000378:metabolism*; D001692:Biological Transport / Q000187:drug effects; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone / Q000494:pharmacology; D002352:Carrier Proteins / Q000378:metabolism; D004024:Dicyclohexylcarbodiimide / Q000494:pharmacology; D004229:Dithiothreitol / Q000494:pharmacology; D004563:Electrochemistry; D004734:Energy Metabolism; D004926:Escherichia coli / Q000201:enzymology*; D005560:Formate Dehydrogenases / Q000378:metabolism*; D006859:Hydrogen / Q000378:metabolism; D007473:Ion Channels / Q000378:metabolism; D009097:Multienzyme Complexes / Q000378:metabolism*; D015221:Potassium Channels / Q000378:metabolism; D027961:Potassium-Hydrogen Antiporters; D006180:Proton-Translocating ATPases / Q000378:metabolism*
D002352:Carrier Proteins; D007473:Ion Channels; D009097:Multienzyme Complexes; D015221:Potassium Channels; D027961:Potassium-Hydrogen Antiporters; D004024:Dicyclohexylcarbodiimide; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone; D006859:Hydrogen; D005560:Formate Dehydrogenases; D000445:Aldehyde Oxidoreductases; D006180:Proton-Translocating ATPases; D004229:Dithiothreitol