Clustering of nitrogen fixation (nif) genes in Rhizobium meliloti
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چکیده
منابع مشابه
Clustering of nitrogen fixation (nif) genes in Rhizobium meliloti.
A cloned 17.3-kilobase region of the Rhizobium meliloti genome with homology to the Klebsiella pneumoniae nitrogenase structural genes was studied. Limits on the extent of homology were determined. Transposon mutagenesis of this region of the genome verified that it contained functional nif genes, Some transposon insertions resulted in a defective symbiotic phenotype, whereas others had no noti...
متن کاملDirected transposon Tn5 mutagenesis and complementation analysis of Rhizobium meliloti symbiotic nitrogen fixation genes.
An 18 kb region adjacent to and surrounding the genes for nitrogenase (nif) was cloned from the genome of the symbiotic nitrogen-fixing species Rhizobium meliloti. A total of 31 Tn5 insertions in the nif region were constructed and assayed for their effect on symbiotic nitrogen fixation (Fix phenotype). Fix- insertions were found in two clusters, one 6.3 kb region not containing essential symbi...
متن کاملIn vitro activity of the nitrogen fixation regulatory protein FIXJ from Rhizobium meliloti.
Cell extracts of an Escherichia coli strain that overproduces the regulatory protein FIXJ from Rhizobium meliloti promoted transcription of fixK, a known FIXJ-dependent gene, in a coupled transcription-translation assay. Activation by FIXJ was dependent on the sigma 70 holoenzyme form of RNA polymerase.
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A set of conserved, or common, bacterial nodulation (nod) loci is required for host plant infection by Rhizobium melioti and other Rhizobium species. Four such genes, nodDABC, have beeii indicated in R. meliloti 021'by genetic analysis and DNA sequencing. An essential step toward Iunderstanding the function of these genes is to characterize their protein products. We used in vitro and maxicell ...
متن کاملRelative Efficacy of Different Alfalfa Cultivar-Rhizobium meliloti Strain Combinations for Symbiotic Nitrogen Fixation.
Five Rhizobium meliloti isolates known to have different capabilities for expression of nitrogenase activity under symbiotic conditions were used to inoculate four representative Medicago sativa cultivars under aseptic conditions. Nitrogenase activities and respiratory activity were measured for whole plants and excised nodules. Dry weights and nodule numbers were also recorded after 4 weeks of...
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ژورنال
عنوان ژورنال: Journal of Bacteriology
سال: 1982
ISSN: 0021-9193,1098-5530
DOI: 10.1128/jb.149.1.221-228.1982