INTERACTION BETWEEN DNA AND AN ESCHERICHIA-COLI PROTEIN OMEGA
INTERACTION BETWEEN DNA AND AN ESCHERICHIA-COLI PROTEIN OMEGA
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DOI：
10.1016/0022-2836(71)90334-2
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发表时间：
1971-01-01
影响因子：
5.6
通讯作者：
WANG, JC
中科院分区：
文献类型：
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作者：
WANG, JC
AnE.大肠杆菌蛋白，命名为ω，已被纯化至少1000倍。用ω处理含有负超螺旋转角的嗜酸性封闭DNA双链体会导致大部分超螺旋转角的丢失。超螺旋圈的损失遵循一个渐进的过程，而不是一个一次性的机制。该反应不需要辅因子。没有检测到DNA物理性质的其他变化。DNA保持共价闭合。它的紫外吸收光谱，圆二色性，在氯化铯中的浮力密度，在含有不同量的乙锭的中性介质中和在碱性介质中的沉降特性，以及它对脉孢菌核酸内切酶的敏感性，与含有相同数目的超螺旋圈的未处理的DNA没有显著不同。因此，ω似乎能够将“旋转体”可逆地引入DNA中。一个合理的机制是假设。
AnE. coliprotein, designated ω, has been purified at least 1000-fold. Treatment of a eovalently closed DNA duplex containing negative superhelical turns with ω results in the loss of most of the superhelical turns. The loss of superhelical turns follows a gradual course rather than a one-hit mechanism. This reaction does not require a cofactor. No other change in the physical properties of the DNA could be detected. The DNA remains covalently closed. Its ultraviolet absorption spectrum, circular dichroism, buoyant density in CsCl, sedimentation properties in neutral media containing varying amounts of ethidium and in an alkaline medium, and its susceptibility towardNeurosporaendonuclease, are not significantly different from an untreated DNA containing the same number of superhelical turns. Thus it appears that ω is capable of introducing a “swivel” reversibly into a DNA. A plausible mechanism is postulated.