The product of the Klebsiella pneumoniae nifX gene is a negative regulator of the nitrogen fixation (nif) regulon.

摘要: An insertional mutation was made in the nifX gene of Klebsiella pneumoniae. This had little effect on nitrogenase activity strain, as measured by acetylene reduction. However, addition NH4+ or O2 (conditions which block nif protein synthesis transcriptional and posttranscriptional mechanisms), NifX- mutant synthesized proteins longer more accumulated nifHDKTY mRNA than did wild-type K. pneumoniae at all time points tested. Conversely, overexpression region blocked synthesis, accumulation, accumulation. These complementary results indicate that a product has role negative regulation response to O2.