title: Affinity chromatographic purification of nucleosomes containing transcriptionally active DNA sequences.
abstract: The unfolding of nucleosome cores in transcriptionally active chromatin uncovers the sulfhydryl groups of histone H3, making them accessible to SH-reagents. This has suggested that nucleosomes from active genes could be retained selectively on organomercurial/agarose columns. When nucleosomes released from rat liver nuclei by limited digestion with micrococcal nuclease were passed through an Hg affinity column, a run-off fraction of compact, beaded nucleosomes was separated from a retained nucleosome fraction. Although both contained monomer-length DNA and a full complement of core histones, histones in the retained fraction were hyperacetylated. Dot blot hybridizations showed the Hg-bound nucleosome fraction to be enriched in DNA sequences transcribed by hepatocytes (serum albumin and transferrin genes), while a brain-specific gene (preproenkephalin) was not retained, but appeared in the nucleosomes of the run-off fraction. The results are discussed in light of other evidence linking hyperacetylation of histones H3 and H4 to conformational changes at the middle of the nucleosome core.
authors: Laboratory of Cell Biology, Rockefeller University, New York, N.Y. 10021.
authors: P
authors: P
authors: Allegra
authors: R
authors: R
authors: Sterner
authors: D F
authors: DF
authors: Clayton
authors: V G
authors: VG
authors: Allfrey
mesh_terms: D000107:Acetylation; D000818:Animals; D001483:Base Sequence; D002846:Chromatography, Affinity; D004247:DNA / Q000032:analysis*; D004591:Electrophoresis, Polyacrylamide Gel; D006657:Histones / Q000032:analysis; D009693:Nucleic Acid Hybridization; D009707:Nucleosomes / Q000032:analysis*; D051381:Rats; D011919:Rats, Inbred Strains; D014158:Transcription, Genetic
chemical_list: D006657:Histones; D009707:Nucleosomes; D004247:DNA