title: Distribution of RNA polymerase binding sites in fractionated chromatin.
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.
mesh_terms: D000605:Amino Alcohols; D000818:Animals; D001665:Binding Sites; D002417:Cattle; D002482:Cellulose / Q000031:analogs & derivatives; D002499:Centrifugation, Density Gradient; D002843:Chromatin / Q000378:metabolism*; D002852:Chromatography, Ion Exchange; D004247:DNA; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology; D004988:Ethers, Cyclic; D007475:Ion Exchange Resins; D012329:RNA, Bacterial / Q000096:biosynthesis; D013950:Thymus Gland / Q000166:cytology; D014158:Transcription, Genetic; D014500:Uracil Nucleotides / Q000378:metabolism
chemical_list: D000605:Amino Alcohols; D002843:Chromatin; C007577:ECTHAM-cellulose; D004988:Ethers, Cyclic; D007475:Ion Exchange Resins; D012329:RNA, Bacterial; D014500:Uracil Nucleotides; D002482:Cellulose; D004247:DNA; D012321:DNA-Directed RNA Polymerases