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Proceedings of the National Academy of Sciences of the United States of America logoLink to Proceedings of the National Academy of Sciences of the United States of America
. 1974 Jul;71(7):2740–2743. doi: 10.1073/pnas.71.7.2740

Distribution of RNA Polymerase Binding Sites in Fractionated Chromatin

Robert T Simpson 1,2
PMCID: PMC388545  PMID: 4604338

Abstract

Calf-thymus chromatin was fractionated by ion-exchange chromatography on ECTHAM-cellulose and sucrose gradient sedimentation. [ECTHAM-cellulose is a cationic adsorbent prepared by coupling tris(hydroxymethyl)aminomethane to cellulose with epichlorohydrin.] The capacity of these fractionated chromatins to support RNA synthesis by DNA-dependent RNA polymerase of Escherichia coli was examined, using procedures that permit measurement of binding site frequency. Unfractionated calf thymus chromatin has 5-10% as many binding sites as protein-free DNA. By combination of the two fractionation methods, chromatin samples were obtained containing as few as 2% and as many as 47% of the number of binding sites found on protein-free DNA.

Keywords: transcription, ECTHAM-cellulose, sucrose gradient sedimentation

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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