The molecular genetics of nitrogen fixation in the bradyrhizobium sp. (parasponia) strain ANU289 (original) (raw)

DNA sequences which encode the iron-molybdenum protein of nitrogenase in the Bradyrhizobium sp. lV (Parasponia) strain ANU289 have been identified, cloned and sequenced to complete the first characterization of nitrogenase in a Rhizobium species. Other sequences have also been identified, cloned and analyzed to reveal six additional regions likely to be necessary for the symbiotic, nitrogen-fixing phenotype of this strain. In strain ANU289, the genes for the two sub-units of the molybdenum-iron protein, nifD and nifK, were isolated by homology to cloned Klebsiella pneumoniae genes. The separation of these genes from the gene encoding the ironprotein of nitrogenase, nifH, was determined to be 20 kb. The role of these genes in nitrogen-fixation was verified by use of a s~ecific, site-directed mutagenesis system which has been developed. Characterization of the nifD and nifK genes reveals the protein structure of their product s to be highly conserved between other nitrogen-fixing orga...

Sign up for access to the world's latest research.

checkGet notified about relevant papers

checkSave papers to use in your research

checkJoin the discussion with peers

checkTrack your impact