DNA supercoiling allows enhancer action over a large distance
- Department of Biochemistry and Molecular Biology, Wayne State University School of Medicine, 540 East Canfield Avenue, Room 5123, Detroit, MI 48201
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Edited by Gary Felsenfeld, National Institutes of Health, Bethesda, MD, and approved October 22, 2001 (received for review September 10, 2001)
Abstract
Enhancers are regulatory DNA elements that can activate their genomic targets over a large distance. The mechanism of enhancer action over large distance is unknown. Activation of the glnAp2 promoter by NtrC-dependent enhancer in Escherichia coli was analyzed by using a purified system supporting multiple-round transcription in vitro. The data suggest that DNA supercoiling is an essential requirement for enhancer action over a large distance (2,500 bp) but not over a short distance (110 bp). DNA supercoiling facilitates functional enhancer–promoter communication over a large distance, probably by bringing the enhancer and promoter into close proximity.
Footnotes
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↵ * Present address: Department of Biochemistry, University of Michigan Medical School, 1301 Catherine Road, Ann Arbor, MI 48109-0606.
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↵ † To whom reprint requests should be addressed. E-mail: vstudit{at}med.wayne.edu.
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This paper was submitted directly (Track II) to the PNAS office.
- Abbreviations:
- sc,
- supercoiled;
- topo I,
- topoisomerase I;
- RPc,
- closed initiation complex;
- RPo,
- open initiation complex
- Copyright © 2001, The National Academy of Sciences
