Regulation of transcription initiation at the Escherichia coli nir operon promoter: a new mechanism to account for co-dependence on two transcription factors
| العنوان: | Regulation of transcription initiation at the Escherichia coli nir operon promoter: a new mechanism to account for co-dependence on two transcription factors |
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| المؤلفون: | Jeffrey A. Cole, Kerry L. Tyson, Stephen J. W. Busby, Hui-chung Wu |
| المصدر: | Molecular Microbiology. 27:493-505 |
| بيانات النشر: | Wiley, 1998. |
| سنة النشر: | 1998 |
| مصطلحات موضوعية: | DNA, Bacterial, Integration Host Factors, Iron-Sulfur Proteins, Nitrite Reductases, Transcription, Genetic, Operon, Molecular Sequence Data, Repressor, Biology, Microbiology, chemistry.chemical_compound, Bacterial Proteins, Transcription (biology), Factor For Inversion Stimulation Protein, Escherichia coli, Binding site, Promoter Regions, Genetic, Molecular Biology, Transcription factor, Sequence Deletion, Binding Sites, Base Sequence, Escherichia coli Proteins, Gene Expression Regulation, Bacterial, Molecular biology, DNA-Binding Proteins, A-site, chemistry, Mutagenesis, bacteria, Carrier Proteins, DNA, Transcription Factors |
| الوصف: | Expression from the Escherichia coli nir promoter is co-dependent on Fnr (a transcription factor triggered by oxygen starvation) and on NarL or NarP (transcription factors triggered by nitrite and nitrate ions). Fnr binds to a single DNA site centred between basepairs 41 and 42 upstream from the nir transcript start, whereas NarL and NarP bind to a site upstream, centred between basepairs 69 and 70. A novel mechanism to account for co-dependence on Fnr and NarL/NarP is suggested from experiments in which the spacing between the DNA sites for Fnr and NarL/NarP was altered. DNA sequence elements located upstream of the NarL/NarP-binding site are the targets for two or more proteins that act to repress Fnr-dependent activation of the nir promoter. This inhibition is counteracted by NarL or NarP. The model has been corroborated by the effects of several deletions and single base substitutions in the nir promoter upstream sequences: these deletions and substitutions prevent the binding of the repressor proteins. One of these repressors has been identified as the Fis protein, that binds to a site located 135-149bp upstream of the nir transcript start: the binding of Fis is suppressed by a single base substitution at position -146. The other repressor protein(s) have yet to be identified, but appear to bind downstream of the DNA site for Fis: binding is suppressed by a single base substitution at position -99. |
| تدمد: | 1365-2958 0950-382X |
| DOI: | 10.1046/j.1365-2958.1998.00699.x |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::9b58dcb1f354d61fef7c2f8e845a9782 https://doi.org/10.1046/j.1365-2958.1998.00699.x |
| Rights: | OPEN |
| رقم الانضمام: | edsair.doi.dedup.....9b58dcb1f354d61fef7c2f8e845a9782 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 13652958 0950382X |
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| DOI: | 10.1046/j.1365-2958.1998.00699.x |