Electron transport to nitrogenase in Klebsiella pneumoniae.

Abstract
Cell-free extracts of nifF and nifJ mutants of K. pneumoniae are unable to couple acetylene reduction (N2 fixation) by nitrogenase to the oxidation of organic metabolites. However, nifF and nifJ mutants can complement each other in vitro to establish the coupling. The products of the nifF and nifJ genes apparently constitute essential elements of the physiological electron pathway to nitrogenase. The electron-transfer-active product of the nifF gene, a flavoprotein, was purified.