Lilley D M, Jacobs M F, Houghton M
Nucleic Acids Res. 1979 Sep 25;7(2):377-99. doi: 10.1093/nar/7.2.377.
The integrity and stability of nucleosomes under transcription assay conditions has been found to depend on concentration and ionic environment. Rifamycin AF/013, a commonly used inhibitor of initiation, is particularly effective in destabilisation of nucleosomes. Intact nucleosomes are refractory to transcription by wheat RNA polymerase II, the histone core preventing initiation. Template titration suggests that the polymerase can, however, bind to nucleosomes, and a 15--16S complex has been observed on sucrose gradients. DNase I digestion of polymerase-nucleosome incubations indicates that whilst histone is still present in the complex, the nucleosome conformation is altered resulting in enhanced nucleolysis at sites near the DNA centre but reduced overall kinetics of digestion.
已发现核小体在转录分析条件下的完整性和稳定性取决于浓度和离子环境。利福霉素AF/013是一种常用的起始抑制剂，在使核小体不稳定方面特别有效。完整的核小体对小麦RNA聚合酶II的转录具有抗性，组蛋白核心会阻止起始。模板滴定表明，然而，聚合酶可以与核小体结合，并且在蔗糖梯度上观察到了一个15 - 16S的复合物。对聚合酶 - 核小体孵育物进行DNase I消化表明，虽然复合物中仍存在组蛋白，但核小体构象发生了改变，导致在DNA中心附近的位点处核酸分解增强，但总体消化动力学降低。
