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The C-terminal domain of the Escherichia coli RNA polymerase α subunit plays a role in the CI-dependent activation of the bacteriophage λ pM promoter
- Source :
- Nucleic Acids Research
- Publication Year :
- 2007
- Publisher :
- Oxford University Press, 2007.
-
Abstract
- The bacteriophage lambda p(M) promoter is required for maintenance of the lambda prophage in Escherichia coli, as it facilitates transcription of the cI gene, encoding the lambda repressor (CI). CI levels are maintained through a transcriptional feedback mechanism whereby CI can serve as an activator or a repressor of p(M). CI activates p(M) through cooperative binding to the O(R)1 and O(R)2 sites within the O(R) operator, with the O(R)2-bound CI dimer making contact with domain 4 of the RNA polymerase sigma subunit (sigma(4)). Here we demonstrate that the 261 and 287 determinants of the C-terminal domain of the RNA polymerase alpha subunit (alphaCTD), as well as the DNA-binding determinant, are important for CI-dependent activation of p(M). We also show that the location of alphaCTD at the p(M) promoter changes in the presence of CI. Thus, in the absence of CI, one alphaCTD is located on the DNA at position -44 relative to the transcription start site, whereas in the presence of CI, alphaCTD is located at position -54, between the CI-binding sites at O(R)1 and O(R)2. These results suggest that contacts between CI and both alphaCTD and sigma are required for efficient CI-dependent activation of p(M).
- Subjects :
- Gene Expression Regulation, Viral
Transcriptional Activation
Protein subunit
Repressor
Biology
DNA-binding protein
chemistry.chemical_compound
Viral Proteins
Transcription (biology)
RNA polymerase
Genetics
Viral Regulatory and Accessory Proteins
Promoter Regions, Genetic
Molecular Biology
Models, Genetic
Activator (genetics)
C-terminus
Escherichia coli Proteins
DNA-Directed RNA Polymerases
Molecular biology
Bacteriophage lambda
Protein Structure, Tertiary
DNA-Binding Proteins
Repressor Proteins
chemistry
Amino Acid Substitution
DNA
Subjects
Details
- Language :
- English
- ISSN :
- 13624962 and 03051048
- Volume :
- 35
- Issue :
- 7
- Database :
- OpenAIRE
- Journal :
- Nucleic Acids Research
- Accession number :
- edsair.doi.dedup.....17308a0df2cb99c5b5945192ff665879