Shestakov S V, Postnova T I, Shakhnabatian L G
Mol Biol Rep. 1975 Jul;2(2):89-94. doi: 10.1007/BF00357537.
The cell-free extract from blue-green alga Anacystis nidulans contains enzymatic activities which repair in vitro transforming DNA of bacteriophage T4 damaged by UV light or X-rays. The repair effect of the extract was observed with double-stranded irradiated DNA but not with denatured irradiated DNA. The level of restoration of the transforming activity depends on the protein concentration in the reaction mixture and on the dose of irradiation. A fraction of DNA lesions induced by X-rays is repaired by a NAD-dependent polynucleotide ligase present in the extract. The repair of UV-induced lesions is the most efficient in the presence of magnesium ions, NAD, ATP and the four deoxynucleoside triphosphates. The results indicate that the repair of UV-irradiated DNA is performed with the participation of DNA polymerase and polynucleotide ligase which function in the cell-free extract of the algae on the background of a low deoxyribonuclease activity.
来自蓝藻集胞藻的无细胞提取物含有一些酶活性，这些酶活性能够在体外修复被紫外线或X射线损伤的噬菌体T4的转化DNA。提取物对双链辐照DNA有修复作用，但对变性辐照DNA则没有。转化活性的恢复水平取决于反应混合物中的蛋白质浓度和辐照剂量。提取物中存在的一种依赖NAD的多核苷酸连接酶可修复一部分由X射线诱导的DNA损伤。在镁离子、NAD、ATP和四种脱氧核苷三磷酸存在的情况下，紫外线诱导损伤的修复效率最高。结果表明，紫外线辐照DNA的修复是在藻类无细胞提取物中低脱氧核糖核酸酶活性的背景下，由DNA聚合酶和多核苷酸连接酶参与进行的。
