A mutational analysis of DNA mimicry by ocr, the gene 0.3 antirestriction protein of bacteriophage T7
Autor: | Alan Cooper, Rachel Turkington, David T. F. Dryden, Margaret Nutley, Gareth A. Roberts, Emily H. Pritchard, Augoustinos S. Stephanou, Mark R. Tock |
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Rok vydání: | 2009 |
Předmět: |
Base pair
DNA Mutational Analysis Molecular Sequence Data Biophysics Biochemistry Protein Structure Secondary Bacterial cell structure Bacteriophage Viral Proteins chemistry.chemical_compound In vivo Bacteriophage T7 Escherichia coli Amino Acid Sequence Molecular Biology Gene chemistry.chemical_classification biology Molecular Mimicry DNA Restriction Enzymes Cell Biology biology.organism_classification Molecular biology In vitro Enzyme chemistry Dimerization DNA |
Zdroj: | Biochemical and Biophysical Research Communications. 378:129-132 |
ISSN: | 0006-291X |
Popis: | The ocr protein of bacteriophage T7 is a structural and electrostatic mimic of approximately 24 base pairs of double-stranded B-form DNA. As such, it inhibits all Type I restriction and modification (R/M) enzymes by blocking their DNA binding grooves and inactivates them. This allows the infection of the bacterial cell by T7 to proceed unhindered by the action of the R/M defence system. We have mutated aspartate and glutamate residues on the surface of ocr to investigate their contribution to the tight binding between the EcoKI Type I R/M enzyme and ocr. Contrary to expectations, all of the single and double site mutations of ocr constructed were active as anti-R/M proteins in vivo and in vitro indicating that the mimicry of DNA by ocr is very resistant to change. |
Databáze: | OpenAIRE |
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