H2 consumption by Escherichia coli coupled via hydrogenase 1 or hydrogenase 2 to different terminal electron acceptors.
Hydrogen uptake in the presence of various terminal electron acceptors was examined in Escherichia coli mutants synthesizing either hydrogenase 1 or hydrogenase 2. Both hydrogenases mediated nitrate-dependent H2 consumption but neither of them was coupled with nitrite. Unlike hydrogenase 2, hydrogenase 1 demonstrated poor activity with electron acceptors of low midpoint redox potential. Oxygen-linked H2 uptake via hydrogenase 1 was observed over a wide range of air concentrations. Hydrogenase 2 catalyzed this reaction only at low air concentrations. Thus, hydrogenase 1 works in cells at higher redox potential, being more tolerant to oxygen than hydrogenase 2.
Laurinavichene
T V
TV
Institute of Basic Biological Problems, Russian Academy of Sciences, 142290, Pushchino, Moscow Region, Russia.
Tsygankov
A A
AA
D004579:Electron Transport; D004789:Enzyme Activation; D004926:Escherichia coli / Q000201:enzymology / Q000378:metabolism*; D006859:Hydrogen / Q000378:metabolism*; D006864:Hydrogenase / Q000302:isolation & purification / Q000378:metabolism*; D007700:Kinetics; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000302:isolation & purification / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism
D006859:Hydrogen; D010088:Oxidoreductases; C029746:uptake hydrogenase; D006864:Hydrogenase; D010100:Oxygen