Bram S, Hellio R, Kouprach S
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We show that freeze-etching electron microscopy preserves and visualizes chromatin structure at level 25 A. Chromatin depleted of histone H 1 is observed to consist of subunits each having a central asymmetric core of DNA and protein 100 by 120 A. Around this core is wound a loop of DNA containing about 130 base pairs and perhaps some protein.
我们发现，冷冻蚀刻电子显微镜能够在25埃的水平上保存并呈现染色质结构。观察到不含组蛋白H1的染色质由亚基组成，每个亚基都有一个由DNA和蛋白质构成的中心不对称核心，尺寸为100×120埃。围绕这个核心缠绕着一个包含约130个碱基对以及可能一些蛋白质的DNA环。
