StpA protein from Escherichia coli condenses supercoiled DNA in preference to linear DNA and protects it from digestion by DNase I and EcoKI
| Autor: | David T. F. Dryden, Steven A. Keatch, John E. Ladbury, Paul G. Leonard |
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| Jazyk: | angličtina |
| Rok vydání: | 2005 |
| Předmět: |
DNA
Bacterial DNA damage DNA polymerase II Biology Article 03 medical and health sciences Adenosine Triphosphate Genetics Deoxyribonuclease I Protein–DNA interaction Replication protein A 030304 developmental biology chemistry.chemical_classification 0303 health sciences DNA ligase DNA clamp DNA Superhelical Escherichia coli Proteins 030302 biochemistry & molecular biology DNA Restriction Enzymes Molecular biology DNA-Binding Proteins chemistry biology.protein DNA supercoil In vitro recombination Molecular Chaperones |
| Zdroj: | Keatch, S A, Leonard, P G, Ladbury, J E & Dryden, D T F 2005, ' StpA protein from Escherichia coli condenses supercoiled DNA in preference to linear DNA and protects it from digestion by DNase I and EcoKI ', Nucleic Acids Research, vol. 33, no. 20, pp. 6540-6546 . https://doi.org/10.1093/nar/gki951 Nucleic Acids Research |
| ISSN: | 0305-1048 |
| Popis: | The nucleoid-associated protein, StpA, of Escherichia coli binds non-specifically to double-stranded DNA (dsDNA) and apparently forms bridges between adjacent segments of the DNA. Such a coating of protein on the DNA would be expected to hinder the action of nucleases. We demonstrate that StpA binding hinders dsDNA cleavage by both the non-specific endonuclease, DNase I, and by the site-specific type I restriction endonuclease, EcoKI. It requires approximately one StpA molecule per 250-300 bp of supercoiled DNA and approximately one StpA molecule per 60-100 bp on linear DNA for strong inhibition of the nucleases. These results support the role of StpA as a nucleoid-structuring protein which binds DNA segments together. The inhibition of EcoKI, which cleaves DNA at a site remote from its initial target sequence after extensive DNA translocation driven by ATP hydrolysis, suggests that these enzymes would be unable to function on chromosomal DNA even during times of DNA damage when potentially lethal, unmodified target sites occur on the chromosome. This supports a role for nucleoid-associated proteins in restriction alleviation during times of cell stress. |
| Databáze: | OpenAIRE |
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