title: Rhizobium meliloti ntrA (rpoN) gene is required for diverse metabolic functions.
abstract: We report the identification and cloning of an ntrA-like (glnF rpoN) gene of Rhizobium meliloti and show that the R. meliloti ntrA product (NtrA) is required for C4-dicarboxylate transport as well as for nitrate assimilation and symbiotic nitrogen fixation. DNA sequence analysis showed that R. meliloti NtrA is 38% homologous with Klebsiella pneumoniae NtrA. Subcloning and complementation analysis suggested that the R. meliloti ntrA promoter lies within 125 base pairs of the initiation codon and may be constitutively expressed.
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D001692:Biological Transport; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D004251:DNA Transposable Elements; D012321:DNA-Directed RNA Polymerases / Q000502:physiology; D003998:Dicarboxylic Acids / Q000378:metabolism; D005786:Gene Expression Regulation; D005798:Genes, Bacterial; D005816:Genetic Complementation Test; D009154:Mutation; D009584:Nitrogen / Q000378:metabolism; D010641:Phenotype; D011401:Promoter Regions, Genetic; D012231:Rhizobium / Q000235:genetics*; D012808:Sigma Factor / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics*
chemical_list: D004251:DNA Transposable Elements; D003998:Dicarboxylic Acids; D012808:Sigma Factor; D014157:Transcription Factors; D012321:DNA-Directed RNA Polymerases; D009584:Nitrogen