Hamelin C, Yaniv M
Nucleic Acids Res. 1979 Oct 10;7(3):679-87. doi: 10.1093/nar/7.3.679.
A fraction of the cellular nicking-closing (NC) enzyme cosediments with SV40 chromatin isolated after Triton X-100 treatment of infected cells nuclei. Extraction of viral DNA according to the Hirt procedure by treatment of infected cells with sodium dodecyl sulfate (SDS) followed by sedimentation in sucrose gradient to separate the DNA from the bulk of detergent also revealed NC activity associated with DNA. Reconstitution experiments showed that only prebinding of the NC enzyme to DNA protects it against irreversible inactivation by SDS. These results suggest that a fraction of the cellular NC activity is indeed associated with the viral chromosome in vivo.
在对感染细胞核进行Triton X-100处理后分离得到的SV40染色质中，有一部分细胞切口-封闭（NC）酶会发生共沉降。按照Hirt方法，用十二烷基硫酸钠（SDS）处理感染细胞，然后在蔗糖梯度中沉降以将DNA与大部分去污剂分离，提取病毒DNA，结果也显示NC活性与DNA相关。重组实验表明，只有NC酶预先与DNA结合才能保护其不被SDS不可逆地失活。这些结果表明，一部分细胞NC活性在体内确实与病毒染色体相关。
