Carrier W L, Setlow R B
J Bacteriol. 1970 Apr;102(1):178-86. doi: 10.1128/jb.102.1.178-186.1970.
An endonuclease purified approximately 3,200-fold from Micrococcus luteus is active on native ultraviolet-irradiated deoxyribonucleic acid (DNA), but is inactive on unirradiated native or denatured DNA and has no activity toward irradiated denatured DNA. The major type of lesion for the nucleolytic activity is the cyclobutane pyrimidine dimer. The enzyme makes a number of single-strand breaks approximately equal to the number of dimers, but dimers are not excised. This endonuclease-a small molecular weight protein-therefore has all the attributes hypothesized for the first enzyme in the sequential steps in repair of DNA in vivo. Another paper shows that the endonuclease is able to reactivate ultraviolet-irradiated transforming DNA.
一种从藤黄微球菌中纯化出来、纯化倍数约为3200倍的核酸内切酶,对天然的紫外线照射的脱氧核糖核酸(DNA)有活性,但对未照射的天然或变性DNA无活性,且对照射过的变性DNA也没有活性。核酸水解活性的主要损伤类型是环丁烷嘧啶二聚体。该酶产生的单链断裂数量与二聚体数量大致相等,但二聚体并未被切除。因此,这种核酸内切酶——一种小分子量蛋白质——具有体内DNA修复连续步骤中第一种酶所假设的所有特性。另一篇论文表明,该核酸内切酶能够使紫外线照射的转化DNA重新激活。