PMID:8306968
| Citation |
Tupper, AE, Owen-Hughes, TA, Ussery, DW, Santos, DS, Ferguson, DJ, Sidebotham, JM, Hinton, JC and Higgins, CF (1994) The chromatin-associated protein H-NS alters DNA topology in vitro. EMBO J. 13:258-68 |
|---|---|
| Abstract |
H-NS is one of the two most abundant proteins in the bacterial nucleoid and influences the expression of a number of genes. We have studied the interaction of H-NS with DNA; purified H-NS was demonstrated to constrain negative DNA supercoils in vitro. This provides support for the hypothesis that H-NS influences transcription via changes in DNA topology, and is evidence of a structural role for H-NS in bacterial chromatin. The effects of H-NS on topology were only observed at sub-saturating concentrations of the protein. In addition, a preferred binding site on DNA was identified by DNase I footprinting at sub-saturating H-NS concentrations. This site corresponded to a curved sequence element which we previously showed, by in vivo studies, to be a site at which H-NS influences transcription of the proU operon. When present in saturating concentrations, H-NS did not constrain supercoils and bound to DNA in a sequence-independent fashion, covering all DNA molecules from end to end, suggesting that H-NS may form distinct complexes with DNA at different H-NS:DNA ratios. The data presented here provide direct support for the hypothesis that H-NS acts at specific sites to influence DNA topology and, hence, transcription. |
| Links | |
| Keywords |
Bacterial Proteins; Base Sequence; Chromatin/metabolism; DNA, Bacterial/chemistry; DNA, Bacterial/metabolism; DNA, Bacterial/ultrastructure; DNA-Binding Proteins/metabolism; DNA-Binding Proteins/ultrastructure; Deoxyribonuclease I; Molecular Sequence Data; Nuclear Proteins/metabolism; Nuclear Proteins/ultrastructure; Nucleic Acid Conformation; Osmolar Concentration; Promoter Regions, Genetic; Protein Binding; Salmonella typhimurium; Transcription, Genetic |
| edit table |
Significance
You can help EcoliWiki by summarizing why this paper is useful
Useful Materials and Methods
You can help Ecoliwiki by describing the useful materials (strains, plasmids, antibodies, etc) described in this paper.
Annotations
<annotationlinks/>
EcoliWiki Links
Add links to pages that link here (e.g. gene, product, method pages)
References
See Help:References for how to manage references in EcoliWiki.