Nickol J, Behe M, Felsenfeld G
Proc Natl Acad Sci U S A. 1982 Mar;79(6):1771-5. doi: 10.1073/pnas.79.6.1771.
We have studied the properties of complexes formed between histones and the methylated synthetic polydeoxynucleotide poly(dG-m5dC). poly(dG-m5dC). This polymer undergoes the transition from B DNA to left-handed Z DNA at moderate ionic strength. When the polymer is in the Z form it will bind histones, but nucleosomes are not detected. When the polymer in the B form is combined with equimolar quantities of the four core histones and digested with micrococcal nuclease, particles are formed which behave in all respects as normal nucleosome cores. When these core particles are placed in solvents that would result in conversion of the protein-free polymer to the Z form, no transition is observed. The formation of a nucleosome core particle thus stabilizes the B form, whereas the presence of the Z form prevents nucleosome formation. The results suggest that if Z DNA is present in eukaryotic nuclei, it will serve to disrupt the normal chromatin structure.
我们研究了组蛋白与甲基化的合成多脱氧核苷酸聚（dG-m5dC）·聚（dG-m5dC）形成的复合物的性质。这种聚合物在中等离子强度下会从B型DNA转变为左手Z型DNA。当聚合物处于Z型时，它会结合组蛋白，但未检测到核小体。当B型聚合物与等摩尔量的四种核心组蛋白结合并用微球菌核酸酶消化时，会形成在各方面都表现为正常核小体核心的颗粒。当将这些核心颗粒置于会导致无蛋白聚合物转变为Z型的溶剂中时，未观察到转变。因此，核小体核心颗粒的形成稳定了B型，而Z型的存在则阻止了核小体的形成。结果表明，如果真核细胞核中存在Z型DNA，它将有助于破坏正常的染色质结构。
