[Role of components of formate-hydrogen-lyase in forming molecular hydrogen and their connection with proton-potassium exchange in anaerobically grown Escherichia coli].
It is shown that -2H+/K(+)-exchange through the H(+)-K(+)-pump, formed by the F0F1-ATPase and the Trk H system, H(+)-K(+)-exchange via H(+)-K(+)-antiporter, formed by the F0 and the Trk G (core) system [1-2], and production of H2 in anaerobically grown E.coli are changed in the mutants with defects in components of formate hydrogen lyase complex, oxidizing formate to CO2 and H2. 2H+/K(+)-exchange and H2 production are destroyed, but H(+)-K(+)-exchange with a variable stoichiometry for N,N'-dicyclohexyl-carbodiimide-sensitive ion fluxes is displayed in the fdhF mutant E.coli FM911, where formate dehydrogenase(H) is absent. 2H+/K(+)-exchange does not occur, but H(+)-K(+)-exchange with variable stoichiometry for N,N'-dicyclohexylcarbodiimide-sensitive ion fluxes and H2 production are observed in the uncD mutant E.coli AN817 with defect in beta subunit of the F1. Deletion of the hyc-operon in mutant E.coli HD700, led to absence of hydrogenase 3, destroys H(+)-K(+)-exchange and H2 production. H2 evaluation is shown in the E.coli K12(lambda) protoplasts, treated with toluene, by adding of NADH into the medium, containing ATP and K+. It is inhibited by N,N'-dicyclohexylcarbodiimide. H2 production is increased by adding of dithiothreitol, when NADH is changed by formate. It is lost in the mutants with defects in the F0 (E.coli AN936) or in the Trk A protein (E.coli TK2242). Dehydrogenase(H) and hydrogenase 3 are assumed to link mutually with a H(+)-K(+)-pump operation, reducing equivalents, necessary for a dithiol-disulfide interconversion within a mechanism of pump, are transferred from formate by means of dehydrogenase(H) to hydrogenase 3 through the F0F1 and the Trk H system to produce H2. It is assumed that hydrogenase 3 can interact with a mechanism of H(+)-K(+)-antiporter, NADH could serve as a donor of reducing equivalents. A role of thiol-groups and dithiol-disulfide interconversion in a functions of both mechanism for H(+)-K(+)-exchange is confirmed.
Bagramian
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Trchunian
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D017920:Antiporters / Q000378:metabolism*; D004926:Escherichia coli / Q000254:growth & development / Q000378:metabolism*; D005560:Formate Dehydrogenases; D006859:Hydrogen / Q000737:chemistry / Q000378:metabolism*; D006864:Hydrogenase; D008190:Lyases / Q000378:metabolism*; D009097:Multienzyme Complexes; D009876:Operon; D011188:Potassium / Q000378:metabolism*; D027961:Potassium-Hydrogen Antiporters; D006180:Proton-Translocating ATPases / Q000378:metabolism
D017920:Antiporters; D009097:Multienzyme Complexes; D027961:Potassium-Hydrogen Antiporters; D006859:Hydrogen; D006864:Hydrogenase; D005560:Formate Dehydrogenases; C054017:formate hydrogenlyase; D006180:Proton-Translocating ATPases; D008190:Lyases; D011188:Potassium
Rol' kompenentov formiat-vodorod-liazy v obrazovanii molekuliarnogo vodoroda i ikh sviaz' s protonno-kalievym obmenom u anaérobno vyrashchennykh bakteriĭ Escherichia coli.