Keatch, SA, Leonard, PG, Ladbury, JE orcid.org/0000-0002-6328-7200 et al. (1 more author) (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, 33 (20). pp. 6540-6546. ISSN 0305-1048
Abstract
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.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © The Author 2005. Published by Oxford University Press. All rights reserved The online version of this article has been published under an open access model. Users are entitled to use, reproduce, disseminate, or display the open access version of this article for non-commercial purposes provided that: the original authorship is properly and fully attributed; the Journal and Oxford University Press are attributed as the original place of publication with the correct citation details given; if an article is subsequently reproduced or disseminated not in its entirety but only in part or as a derivative work this must be clearly indicated. For commercial re-use, please contact journals.permissions@oxfordjournals.org. |
Keywords: | Adenosine Triphosphate; DNA Restriction Enzymes; DNA, Bacterial; DNA, Superhelical; DNA-Binding Proteins; Deoxyribonuclease I; Escherichia coli Proteins; Molecular Chaperones |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Biological Sciences (Leeds) > School of Molecular and Cellular Biology (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 08 Sep 2017 12:51 |
Last Modified: | 08 Sep 2017 12:51 |
Status: | Published |
Publisher: | Oxford University Press |
Identification Number: | 10.1093/nar/gki951 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:89275 |