Bradyrhizobium japonicum FixK2, a crucial distributor in the FixLJ-dependent regulatory cascade for control of genes inducible by low oxygen levels

• Published in: Journal of bacteriology Vol. 180; no. 19; pp. 5251 - 5255
• Main Authors: Nellen-Anthamatten, D. (Eidgenossische Technische Hochschule, Zurich, Switzerland.), Rossi, P, Preisig, O, Kullik, I, Babst, M, Fischer, H.M, Hennecke, H
• Format: Journal Article
• Language: English
• Published: United States American Society for Microbiology 01.10.1998
• Series: Note
• Subjects: Amino Acid Sequence; AMINO ACID SEQUENCES; Bacterial Proteins - genetics; Bacterial Proteins - physiology; Bacteriology; Base Sequence; BETA GALACTOSIDASA; BETA GALACTOSIDASE; BRADYRHIZOBIUM JAPONICUM; CHEMICAL COMPOSITION; COMPOSICION QUIMICA; COMPOSITION CHIMIQUE; DNA BINDING MOTIFS; EXPRESION GENICA; EXPRESSION DES GENES; FIXK1 GNEE; FIXK2 GENE; GENBANK/AJ005001; GENE; GENE EXPRESSION; Gene Expression Regulation, Bacterial - physiology; GENES; Genes, Bacterial - genetics; GENETIC REGULATION; GENETICA; GENETICS; GENETIQUE; Hemeproteins - physiology; Models, Genetic; MOLECULAR SEQUENCE DATA; Mutation; NUCLEOTIDE SEQUENCE; Operon - genetics; OPERONS; OXIGENO; OXYGEN; OXYGENE; Plant Microbiology; Proteins; Recombinant Fusion Proteins; REGULATORY GENES; REPORTER GENES; Restriction Mapping; Rhizobiaceae - genetics; Rhizobiaceae - metabolism; SECUENCIA NUCLEOTIDICA; Sequence Homology, Amino Acid; SEQUENCE NUCLEOTIDIQUE; TRANSCRIPCION; TRANSCRIPTION; Transcription, Genetic - genetics; Transcriptional Activation - genetics
• ISSN: 0021-9193; 1098-5530
• DOI: 10.1128/jb.180.19.5251-5255.1998

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