Role of the fixGHI region of Azorhizobium caulinodans in free-living and symbiotic nitrogen fixation

FEMS Microbiol Lett. 1993 Dec 1;114(2):185-9. doi: 10.1111/j.1574-6968.1993.tb06571.x.


A 19-kb DNA region containing genes sharing homology with Rhizobium meliloti fixNOQP and fixGHI was isolated from a genomic library of Azorhizobium caulinodans. Identity of fixG was confirmed by partial nucleotide sequencing. Mutant strains in the fixGHI region were constructed by deletion or Tn5 insertions. In contrast with the situation in R. meliloti, the mutants still displayed a significant nitrogenase activity in symbiosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Cloning, Molecular / methods
  • Gene Expression Regulation, Enzymologic
  • Molecular Sequence Data
  • Mutation / genetics*
  • Nitrogen Fixation / genetics*
  • Nitrogenase / biosynthesis*
  • Rhizobiaceae / enzymology
  • Rhizobiaceae / genetics*
  • Symbiosis


  • Nitrogenase