P22 repressor mutants deficient in co-operative binding and DNA loop formation
| Autor: | M Ptashne, Dario Valenzuela |
|---|---|
| Rok vydání: | 1989 |
| Předmět: |
Operator (biology)
Molecular Sequence Data Mutant Repressor Plasma protein binding Biology DNA-binding protein General Biochemistry Genetics and Molecular Biology chemistry.chemical_compound Salmonella Escherichia coli Binding site Promoter Regions Genetic Molecular Biology Base Sequence General Immunology and Microbiology General Neuroscience Nucleic acid sequence beta-Galactosidase Bacteriophage lambda Molecular biology Repressor Proteins chemistry DNA Viral Mutation Salmonella Phages DNA Research Article Plasmids Protein Binding Transcription Factors |
| Zdroj: | The EMBO Journal. 8:4345-4350 |
| ISSN: | 0261-4189 |
| DOI: | 10.1002/j.1460-2075.1989.tb08621.x |
| Popis: | We show here, both in vivo and in vitro, that P22 repressor binds co-operatively to operator sites separated by an integral number of turns of the DNA helix. We measure this co-operativity in vivo using an assay in which repression of a promoter requires co-operative binding of P22 repressors to two separated (non-adjacent) operator sites. We report the isolation of mutant repressors that have high affinity for single operator sites, but are defective in co-operative binding. Six different mutants, all bearing single amino acid changes in the carboxyl domain, have been isolated. We purified the two mutants most deficient in co-operative binding, and found that they bind non-co-operatively in vitro to adjacent as well as to non-adjacent pairs of operator sites. |
| Databáze: | OpenAIRE |
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