title: Nitrogenase from nifV mutants of Klebsiella pneumoniae contains an altered form of the iron-molybdenum cofactor.
abstract: When the iron-molybdenum cofactor (FeMoco) was extracted from the MoFe protein of nitrogenase from a nifV mutant of Klebsiella pneumoniae and combined with the FeMoco-deficient MoFe protein from a nifB mutant, the resultant MoFe protein exhibited the NifV phenotype, i.e. in combination with wild-type Fe protein it exhibited poor N2-fixation activity and its H2-evolution activity was inhibited by CO. These data provide strong evidence that FeMoco contains the active site of nitrogenase. The metal contents and e.p.r. properties of FeMoco from wild-type and nifV mutants of K. pneumoniae are very similar.
mesh_terms: D001665:Binding Sites; D004578:Electron Spin Resonance Spectroscopy; D005288:Ferredoxins / Q000235:genetics; D006859:Hydrogen / Q000378:metabolism; D007711:Klebsiella pneumoniae / Q000201:enzymology* / Q000235:genetics; D008983:Molybdoferredoxin / Q000235:genetics; D009154:Mutation; D009586:Nitrogen Fixation; D009591:Nitrogenase / Q000235:genetics; D010641:Phenotype
chemical_list: D005288:Ferredoxins; D008983:Molybdoferredoxin; D006859:Hydrogen; D009591:Nitrogenase