Histone deacetylase. Association with a nuclease resistant, high molecular weight fraction of HeLa cell chromatin.

摘要: The chromatin-bound histone deacetylase of HeLa cells has been studied using endogenous [3H]acetyl-labeled polynucleosomes containing the enzyme, prepared in presence 40 mM butyrate. Histone was assayed upon removal butyrate, and it found that active enzyme is only association with a high molecular weight complex. This deacetylase-containing complex relatively resistant to digestion micrococcal nuclease. No activity on mononucleosomes or oligonucleosomes. Up 90% labeled acetyl groups are removed from complexes incubated absence Free histones poor substrate under these conditions, but deacetylated when they remains bound this 1-2 M NaCl does not dissociate during its reaction acetylated core histones. Under typical nuclease contains DNA size distribution 5-11 kilobase pairs variety nonhistone proteins. Comparison protein composition nuclear matrix preparations shows some similarities. Taken together, results chromatographic behavior, fragment sizes, suggest protein-protein interactions may be important maintaining structure also binding itself