In vitro activity of the nitrogen fixation regulatory protein FIXJ from Rhizobium meliloti.
نویسندگان
چکیده
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.
منابع مشابه
Oxygen-regulated in vitro transcription of Rhizobium meliloti nifA and fixK genes.
Oxygen concentration regulates the expression of nitrogen fixation genes in the symbiotic bacterium Rhizobium meliloti. We demonstrate that two proteins, FixL and FixJ, that belong to the two-component family of regulatory proteins are necessary and sufficient for oxygen-regulated in vitro transcription of the two key regulatory genes, nifA and fixK. We show directly that FixJ is a transcriptio...
متن کاملIntramolecular signal transduction within the FixJ transcriptional activator: in vitro evidence for the inhibitory effect of the phosphorylatable regulatory domain.
FixJ is a phosphorylatable 'response regulator' controlling the transcription of the key nitrogen fixation genes nifA and fixK in Rhizobium meliloti. Sequence and genetic analyses indicated that FixJ comprises an N-terminal phosphorylatable regulatory domain, FixJN, and a C-terminal transcriptional activator domain, FixJC. We have now overexpressed and purified the FixJC protein and show that i...
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Transcription of nitrogen fixation (nif and fix) genes in Rhizobium meliloti is induced by a decrease in oxygen concentration. The products of two genes, fixL and fixJ, are responsible for sensing and transmitting the low-oxygen signal. The proteins encoded by fixL and fixJ (FixL and FixJ, respectively) are homologous to a family of bacterial proteins that transduce environmental signals throug...
متن کاملGenetic regulation of nitrogen fixation in rhizobia.
This review presents a comparison between the complex genetic regulatory networks that control nitrogen fixation in three representative rhizobial species, Rhizobium meliloti, Bradyrhizobium japonicum, and Azorhizobium caulinodans. Transcription of nitrogen fixation genes (nif and fix genes) in these bacteria is induced primarily by low-oxygen conditions. Low-oxygen sensing and transmission of ...
متن کاملRhizobium meliloti regulatory gene fixJ activates transcription of R. meliloti nifA and fixK genes in Escherichia coli.
When present in Escherichia coli on the multicopy expression vector pUC19, a Rhizobium meliloti regulatory gene, fixJ, belonging to a two-component regulatory system, activated the expression of two R. meliloti symbiotic genes, nifA and fixK. Primer extension by reverse transcription showed that FixJ stimulates nifA expression in E. coli by activating pnifA.
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ورودعنوان ژورنال:
- Journal of bacteriology
دوره 173 18 شماره
صفحات -
تاریخ انتشار 1991