Region 2.5 of the Escherichia coli RNA polymerase σ70 subunit is responsible for the recognition of the 'extended −10' motif at promoters
| Autor: | Jon A. Bown, Stephen J. W. Busby, Kerry A. Barne, Stephen D. Minchin |
|---|---|
| Rok vydání: | 1997 |
| Předmět: |
DNA
Bacterial Recombinant Fusion Proteins Protein subunit Molecular Sequence Data Sigma Factor Random hexamer Biology General Biochemistry Genetics and Molecular Biology chemistry.chemical_compound Transcription (biology) Sigma factor RNA polymerase Escherichia coli Amino Acid Sequence Binding site Promoter Regions Genetic Molecular Biology Gene Conserved Sequence Genetics Binding Sites Base Sequence General Immunology and Microbiology General Neuroscience Promoter DNA-Directed RNA Polymerases Molecular biology chemistry Mutagenesis Site-Directed Research Article |
| Zdroj: | The EMBO Journal. 16:4034-4040 |
| ISSN: | 1460-2075 0261-4189 |
| DOI: | 10.1093/emboj/16.13.4034 |
| Popis: | At some bacterial promoters, a 5'-TG-3' sequence element, located one base upstream of the -10 hexamer element, provides an essential motif necessary for transcription initiation. We have identified a mutant of the Escherichia coli RNA polymerase sigma70 subunit that has an altered preference for base sequences in this 'extended -10' region. We show that this mutant sigma70 subunit substantially increases transcription from promoters bearing 5'-TC-3' or 5'-TT-3' instead of a 5'-TG-3' motif, located one base upstream of the -10 hexamer. The mutant results from a single base pair substitution in the rpoD gene that causes a Glu to Gly change at position 458 of sigma70. This substitution identifies a functional region in sigma70 that is immediately adjacent to the well-characterized region 2.4 (positions 434-453, previously shown to contact the -10 hexamer). From these results, we conclude that this region (which we name region 2.5) is involved in contacting the 5'-TG-3' motif found at some bacterial promoters: thus, extended -10 regions are recognized by an extended region 2 of the RNA polymerase sigma70 subunit. |
| Databáze: | OpenAIRE |
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