Electron transfer to nitrogenase in Klebsiella pneumoniae. nifF gene cloned and the gene product, a flavodoxin, purified.

The nifF gene of Klebsiella pneumoniae was cloned into a multicopy plasmid in order to construct a strain that synthesizes and retains an elevated concentration of the gene product relative to the wild-type strain. Characterization of the isolated flavodoxin, which serves as an electron donor to nitrogenase, shows unambiguously that it is the product of the nifF gene.