Bradyrhizobium japonicum FixK2, a Crucial Distributor in the FixLJ-Dependent Regulatory Cascade for Control of Genes Inducible by Low Oxygen Levels

AUTOR(ES)

Nellen-Anthamatten, D.

FONTE

American Society for Microbiology

RESUMO

Bradyrhizobium japonicum possesses a second fixK-like gene, fixK2, in addition to the previously identified fixK1 gene. The expression of both genes depends in a hierarchical fashion on the low-oxygen-responsive two-component regulatory system FixLJ, whereby FixJ first activates fixK2, whose product then activates fixK1. While the target genes for control by FixK1 are unknown, there is evidence for activation of the fixNOQP, fixGHIS, and rpoN1 genes and some heme biosynthesis and nitrate respiration genes by FixK2. FixK2 also regulates its own structural gene, directly or indirectly, in a negative way.

Documentos Relacionados

• Bradyrhizobium japonicum NnrR, a Denitrification Regulator, Expands the FixLJ-FixK2 Regulatory Cascade
• Characterization of a fixLJ-regulated Bradyrhizobium japonicum gene sharing similarity with the Escherichia coli fnr and Rhizobium meliloti fixK genes.
• The FixK2 Protein Is Involved in Regulation of Symbiotic Hydrogenase Expression in Bradyrhizobium japonicum
• Oxygen-regulated in vitro transcription of Rhizobium meliloti nifA and fixK genes.
• Rhizobium meliloti regulatory gene fixJ activates transcription of R. meliloti nifA and fixK genes in Escherichia coli.