Enrichment of acetylated histones in polynucleosomes containing high mobility group protein 17 revealed by immunoaffinity chromatography.

The possibility that chromatin domains containing acetylated histones are proximal to domains containing chromosomal high mobility group protein 17 (HMG-17) has been investigated. Oligonucleosomes containing [3H]acetate-labeled histones have been immunofractionated on anti-HMG-17 IgG-Sepharose columns. Ninety-one per cent of the 3H counts present in the oligonucleosomes specifically bound to the anti-HMG-17 column. Extraction of HMG-17 from chromatin by treatment with 0.4 M NaCl abolished the specific binding of acetylated chromatin to the Sepharose columns. Autoradiographic analysis of polyacrylamide gels of the bound fraction revealed that it contained all the major acetylated histone species. We conclude that acetylated histones are present on or near nucleosomes containing protein HMG-17.