Conformation of 145 base pair length poly (dG-dC) . poly (dG-dC) in solution and in association with histones.
Conformation of 145 base pair length poly (dG-dC) . poly (dG-dC) in solution and in association with histones.
复制标题
145个碱基对长度的聚(dG-dC)的构象。
作者：
R. Simpson;H. Shindo
我们研究了poly（dG-dC）的构象。聚（dG-dC）在三种条件下：i）与组蛋白八聚体缔合，ii）单独在离子强度0.1下，和ii）在超过2.5M NaCl的溶液中。与组蛋白结合的聚合物的圆二色性光谱不同于游离聚合物的圆二色性光谱;差异光谱与天然和聚（dA-dT）的圆二色性光谱相似。聚（dA-dT）核颗粒。在前两个条件下，31 P NMR谱是对称的，在109.3 MHz处的线宽分别为91和41 Hz。在高盐中，观察到两个强度相等的31 P峰，证实了Patel等人（1）的最新结果，并表明磷酸二酯骨架的交替几何结构。使用这种高度同质的DNA，我们证实Pohl-Jovin转变（2）是一种分子内重排，不需要完全的链分离。
We have studied the conformation of poly (dG-dC) . poly (dG-dC) in three conditions; i) associated with histones octamers, ii) alone at ionic strength 0.1, and ii) in solutions of over 2.5 M NaCl. The circular dichroism spectrum for the polymer bound to histones differs from that for the free polymer; the difference spectrum is similar to those for native and poly (dA-dT) . poly (dA-dT) core particles. Under the first two conditions, the 31P NMR spectrum is symmetric with line widths of 91 and 41 Hz, respectively, at 109.3 MHz. In high salt, two 31P peaks of equal intensity are observed, confirming recent results of Patel et al. (1) and indicating an alternating geometry for the phosphodiester backbone. Using this highly homogeneous DNA, we confirm that the Pohl-Jovin transition (2) is an intramolecular rearrangement, not requiring complete strand separation.