Extent of duplex DNA underwinding induced by RecA protein binding in the presence of ATP.
Extent of duplex DNA underwinding induced by RecA protein binding in the presence of ATP.
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在 ATP 存在的情况下，RecA 蛋白结合诱导的双链体 DNA 卷绕程度。
DOI：
10.1016/0022-2836(89)90219-2
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发表时间：
1989
影响因子：
5.6
通讯作者：
Cox,MM
中科院分区：
文献类型：
--
作者：
Pugh,BF;Schutte,BC;Cox,MM
本文描述了一种精确测定高度欠绕环状DNA分子超螺旋密度（σ）的方法。使用这种方法，在pH 7.5的ATP存在下，RecA蛋白结合的双链DNA被发现欠绕了39.6%（σ=-0.396），对应于每转17.4个碱基对的螺旋周期。在低水平ATPγS存在下，欠绕增加到41%（每圈17.9个碱基对），与先前报道的每圈18.6个碱基对非常一致。尽管存在广泛的下旋，但RecA蛋白结合产生的DNA拓扑异构体的分布很小。这表明在ATP存在下RecA-双链DNA复合物之间的高度结构均匀性。
A method is described for the accurate determination of the superhelical density (σ) of highly underwound circular DNA molecules. Using this method, duplex DNA bound by RecA protein in the presence of ATP at pH 7.5 is found to be underwound by 39.6% (σ= −0.396), corresponding to a helical periodicity of 17.4 base-pairs per turn. The underwinding is increased to 41% (17.9 base-pairs per turn) in the presence of low levels of ATPγS, in good agreement with the 18.6 base-pairs per turn reported previously. In spite of the extensive underwinding, the distribution of DNA topoisomers produced by RecA protein binding is small. This indicates a high degree of structural uniformity among RecA-double-stranded DNA complexes in the presence of ATP.