Enzymatic activity, hydrolyzing DNA treated with beta-isopropyl-bis-beta-chloroethylamine (HN2-DNA), HN2-DNA exposed at 50 degrees for 1 h, and DNA treated with acid, to acid-soluble fragments was found in extracts from cells of M. lysodeikticus. The endonucleolytic component ofthe indicated activity manifests chromatographic properties on DEAE- and CM-cellulose, close to those for UV-endonuclease. Activity is manifested by UV-irradiated DNA, proflavin, and cyanide. Two electrophoretically homogeneous fractions of UV-endonuclease (after chromatography on DEAE- and CM-cellulose), with molecular weights about 13,000 and 15,000 daltons, exhibit endonucleolytic activity with respect to HN2-DNA, exposed at 50 degrees for 1 h, and with respect to "acid" DNA, treated for 6 min at 70 degrees in citrate buffer, pH 3.5. The activity with respect to the latter substrate is competitively suppressed by UV-irradiated DNA. The most probable substrate of UV-endonuclease, in addition to cyclobutane dimers, is the depurinized region of DNA.

中文翻译：

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溶菌微球菌细胞中存在一种作用于紫外线照射和去嘌呤化的DNA的核酸内切酶。

在细胞提取物中发现了酶活性，水解用β-异丙基-双-β-氯乙胺（HN2-DNA）处理的DNA，在50度下暴露1 h的HN2-DNA以及经酸处理的DNA到酸溶性片段lysodeikticus。所示活性的内切核酸成分在DEAE-和CM-纤维素上表现出色谱特性，接近于UV-核酸内切酶。活性通过紫外线照射的DNA，黄素和氰化物来证明。UV-核酸内切酶的两个电泳均质级分（在DEAE-和CM-纤维素上色谱分离后），分子量分别约为13,000和15,000道尔顿，对HN2-DNA表现出内切核酸活性，在50度下暴露1 h，相对于HN2-DNA到“酸性” DNA，在柠檬酸缓冲液（pH 3.5）中于70度处理6分钟。相对于后一种底物的活性被紫外线照射的DNA竞争性地抑制。除环丁烷二聚体外，最有可能的紫外线核酸内切酶底物是DNA的纯净区域。