Excision of cytosine hydrates from Z-DNA.
Excision of cytosine hydrates from Z-DNA.
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从 Z-DNA 中切除胞嘧啶水合物。
DOI：
10.1093/nar/18.8.2007
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发表时间：
1990
影响因子：
14.9
通讯作者：
Weems,KM
中科院分区：
文献类型：
--
作者：
Duker,NJ;Weems,KM
紫外线照射DNA产生水合胞嘧啶，作为游离碱基被大肠杆菌内切酶释放。通过测定放射标记的多聚（dG-dC）和多聚（dGdC）的光产物释放量来研究胞嘧啶水合物的切除。B-DNA和2-DNA之间的构象转移是通过在氯化镍或氯化钴中加热聚合物来实现的，并通过圆二色性来确定。酶解水合胞嘧啶的释放速率在不同底物构象之间没有差异。左旋聚（dG-dC）辐照：聚（dG-dC）导致胞嘧啶水合物形成。因此，紫外线诱导的胞嘧啶水合物的形成和酶切都不受这些DNA构象状态的实质性影响。
Ultraviolet irradiation of DNA produces cytosine hydrate, released as a free base by E. coli endonuclease Ill. Cytosine hydrate excision was investigated by assaying photoproduct release from cytosine-radiolabeled, irradiated poly(dG-dC):poly(dGdC). Conformational shifts between B-DNA and 2-DNA were effected by heating the polymer in either nickel chloride or cobaltous chloride, and were determined by circular dichroism. Rates of enzymic cytosine hydrate release did not differ between the different substrate conformations. Irradiation of left-handed poly(dG-dC):poly(dG-dC) resulted in cytosine hydrate formation. Therefore, neither formation nor enzymic excision of ultraviolet-induced cytosine hydrates are substantially affected by these DNA conformational states.