Nitrogen Fixation by Azotobacter vinelandii
نویسنده
چکیده
Nitrogenase was isolated and purified from wildtype and a tungsten-resistant mutant (LM2) of Azotobacter vinelandii strain OP derepressed on medium containing 1-10 mM W. While the enzyme from the wild-type strain contained the polypeptides of the conventional enzyme, metal analysis of component 1 demonstrated the existence of one atom each of molybdenum and tungsten. Furthermore, the ESR spectrum of this protein contained three signals, two f which originated from S = 312 spin states. One of these signals is nearly identical to that of the conventional MoFe-protein while the other is hypothesized to originate from a W-containing cofactor. In spite of the presence of W, the substrate reduction pattern of this enzyme is the same as that of the conventional enzyme.
منابع مشابه
Respiratory Protection of Nitrogenase Activity in <Emphasis Type="Italic">Azotobacter vinelandii</Emphasis>Roles of the Terminal Oxidases
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