The Expression of a Third Nitrogenase in the Cyanobacterium Anabaena variabilis
نویسنده
چکیده
Physiological experiments indicate that Anabaena variabilis can express either a Vor a Fe-nitrogenase in addition to the conventional, Mo-containing enzyme complex. The occur rence o f the Fe-nitrogenase in A. variabilis can also be concluded from D N A -D N A hybridiza tion experiments using cloned anfW or nifW probes coding for the smaller subunit (= nitroge nase reductase) o f the Fe-nitrogenase from Azotobacter vinelandii or for the same subunit o f the Mo-nitrogenase from Klebsiella pneumoniae. The cyanobacterium A. variabilis is the first phototroph found to contain all three nitrogenases landii as yet. Vanadium cannot substitute for M o in
منابع مشابه
Characterization of genes for a second Mo-dependent nitrogenase in the cyanobacterium Anabaena variabilis.
Anabaena variabilis ATCC 29413 is a filamentous heterocystous cyanobacterium that fixes nitrogen under a variety of environmental conditions. Under aerobic growth conditions, nitrogen fixation depends upon differentiation of heterocysts and expression of either a Mo-dependent nitrogenase or a V-dependent nitrogenase in those specialized cells. Under anaerobic conditions, a second Mo-dependent n...
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