Free DNA stretches in histone H1-depleted chromatin and their possible relation to chromomere structure
Free DNA stretches in histone H1-depleted chromatin and their possible relation to chromomere structure
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组蛋白 H1 耗尽的染色质中的游离 DNA 延伸及其与染色体结构的可能关系
DOI：
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发表时间：
1976
影响因子：
2.8
通讯作者：
G. Georgiev
中科院分区：
文献类型：
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作者：
A. Varshavsky;G. Georgiev
通过用葡萄球菌核酸酶温和消化染色质，然后通过凝胶色谱法纯化高分子量物质（六核小体和较大的DNP颗粒），制备染色质亚基的寡聚体（寡核小体）。主要发现是在没有任何明显的流体动力学剪切的情况下，用tRNA从寡核体制备物中温和地去除组蛋白H1，导致游离DNA分子的形成，游离DNA分子占总寡核体DNA的5-6%，在去除H1的流体动力学剪切的染色质中，游离核体DNA片段的大小约为6000个碱基对，其含量显然为10-12%的总DNA。这些和相关的研究结果进行了讨论，在以前提出的“不对称发夹”模型的DNA包装在染色质[1-4]。不同种类的不对称发夹被认为是在解释实验数据的歧义指出。
Oligomers of chromatin subunits (oligonucleosomes) were prepared by a mild digestion of chromatin with staphylococcal nuclease followed by a purification of a high molecular weight material (hexanucleosomes and larger DNP particles) by gel chromatography. The main finding is that a mild removal of histone H1 from the oligonucleosome preparation by treatment with tRNA in the absence of any significant hydrodynamic shearing leads to the formation of free DNA molecules which constitute 5–6% of the total oligonucleosomal DNA.The size of nucleosome-free DNA stretches in H1-depleted hydrodynamically sheared chromatin is about 6000 base pairs and their content is apparently 10–12% of the total DNA. These and related findings are discussed in terms of the previously proposed ‘asymmetric hairpin’ model of DNA packing in chromatin [1–4]. Different kinds of the asymmetric hairpin are considered and ambiguities in interpretations of experimental data are pointed out.