PMID:2571609

Citation	No author listed (1989) Activation of glnA transcription by nitrogen regulator I (NRI)-phosphate in Escherichia coli: evidence for a long-range physical interaction between NRI-phosphate and RNA polymerase. J. Bacteriol. 171:5512-22
Abstract	Growth of cells of Escherichia coli in nitrogen-limited medium induces the formation of glutamine synthetase, product of the glnA gene, and of other proteins that facilitate the assimilation of nitrogen-containing compounds. Transcription from the glnAp2 promoter of the glnALG operon requires the phosphorylation of nitrogen regulator I (NRI) and, for optimal transcription, the binding of NRI-phosphate to two sites that can be over 1,000 base pairs from the binding site for RNA polymerase. In other procaryotic genes, placement of an activator-binding site further upstream from the start site of transcription diminishes expression. To determine how NRI-phosphate activates transcription and why NRI-dependent transcription differs from activation in other systems, we constructed recombinant plasmids with small alterations between the binding sites for NRI-phosphate and RNA polymerase and between the two high-affinity NRI-binding sites. We demonstrate that tightly bound NRI-phosphate activated transcription from either side of the DNA helix when at least 30 base pairs separated NRI-phosphate from RNA polymerase. In contrast, activation from a partial NRI-binding site was effective only from one side of the DNA. We also observed that glnA expression was optimal when the two high-affinity NRI-binding sites were on the same side of the DNA helix. We explain these results on the basis of a hypothesis that a contact between RNA polymerase and NRI-phosphate bound to an upstream site determines the rate of glnA transcription.
Links	PubMed PMC210391
Keywords	Bacterial Proteins; DNA Mutational Analysis; DNA, Bacterial/genetics; DNA-Binding Proteins/genetics; DNA-Directed RNA Polymerases/metabolism; Escherichia coli/genetics; Escherichia coli Proteins; Gene Expression Regulation, Bacterial; Genes, Bacterial; Glutamate-Ammonia Ligase/genetics; PII Nitrogen Regulatory Proteins; Phosphorylation; Plasmids; Promoter Regions, Genetic; Regulatory Sequences, Nucleic Acid; Trans-Activators; Transcription Factors/genetics; Transcription, Genetic
edit table

Significance

You can help EcoliWiki by summarizing why this paper is useful

Useful Materials and Methods

You can help Ecoliwiki by describing the useful materials (strains, plasmids, antibodies, etc) described in this paper.

Annotations

<annotationlinks/>

EcoliWiki Links

Add links to pages that link here (e.g. gene, product, method pages)

References

See Help:References for how to manage references in EcoliWiki.