Murphy R F, Wallace R B, Bonner J
Proc Natl Acad Sci U S A. 1980 Jun;77(6):3336-40. doi: 10.1073/pnas.77.6.3336.
The properties of chromatin containing newly synthesized DNA and protein were investigated. A fraction of chromatin enriched in newly replicated DNA was isolated by means of its increased density in metrizamide relative to bulk chromatin. The DNA of this fraction appeared to be packaged into nucleosomes but at a reduced nucleosomal spacing. Although pulse-labeled DNA was present in this dense fraction, nucleosomes labeled with short pulses of arginine or acetate were of normal density. The data presented are consistent with the conclusion that newly replicated DNA is associated with preexisting histones in a short-lived, compact structure whereas newly synthesized histones are deposited at normal spacing some distance from the replication fork.
对含有新合成DNA和蛋白质的染色质特性进行了研究。通过在甲泛影酰胺中相对于整体染色质密度增加,分离出一部分富含新复制DNA的染色质。该部分的DNA似乎被包装成核小体,但核小体间距减小。尽管脉冲标记的DNA存在于这个致密部分,但用精氨酸或乙酸盐短脉冲标记的核小体密度正常。所呈现的数据与以下结论一致:新复制的DNA以一种短暂的紧密结构与预先存在的组蛋白相关联,而新合成的组蛋白则以正常间距沉积在距复制叉一定距离处。