Quantitative comparison of DNA looping in vitro and in vivo:: chromatin increases effective DNA flexibility at short distances
Quantitative comparison of DNA looping in vitro and in vivo:: chromatin increases effective DNA flexibility at short distances
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DOI：
10.1093/emboj/18.23.6630
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发表时间：
1999-12-01
期刊：
影响因子：
11.4
通讯作者：
Stewart, AF
中科院分区：
文献类型：
--
作者：
Ringrose, L;Chabanis, S;Stewart, AF
线性 DNA 分子上的两个位点通过成环相互接触的概率取决于 DNA 的灵活性。尽管体外裸露 DNA 的灵活性已得到很好的表征，但对染色质的环化却知之甚少。通过扩展现有理论，我们提出了一个描述 DNA 在所有距离上循环的方程。我们还表明，可以通过 74 bp 到 15 kb 之间的位点之间的 FLP 重组来准确测量体外 DNA 环。与之前的工作一致，确定了 50 nm 的持久长度。哺乳动物细胞中相同底物的 FLP 重组表明，染色质增加了短距离 DNA 的灵活性，表观持久长度为 27 nm。
The probability that two sites on a linear DNA molecule will contact each other by looping depends on DNA flexibility. Although the flexibility of naked DNA in vitro is well characterized, looping in chromatin is poorly understood. By extending existing theory, we present a single equation that describes DNA looping over all distances. We also show that DNA looping in vitro can be measured accurately by FLP recombination between sites from 74 bp to 15 kb apart. In agreement with previous work, a persistence length of 50 nm was determined. FLP recombination of the same substrates in mammalian cells showed that chromatin increases the flexibility of DNA at short distances, giving an apparent persistence length of 27 nm.