Lemaire M A, Schwartz A, Rahmouni A R, Leng M
Centre de Biophysique Moléculaire, Orléans, France.
Proc Natl Acad Sci U S A. 1991 Mar 1;88(5):1982-5. doi: 10.1073/pnas.88.5.1982.
A DNA restriction fragment with convergent SP6 and T7 promoters has undergone reaction with cis-diamminedichloroplatinum(II) (cis-DDP) and was then used as a template for RNA synthesis in vitro. The T7 and SP6 RNA polymerases generate fragments of defined sizes. Analysis of the RNA fragments shows that the polymerases are mainly blocked at the level of the d(GG) and d(AG) sites and to a lesser extent at the level of the d(GC) sites. The adducts at the d(GC) sites are more resistant to cyanide ion attack than those at the major sites and are identified as interstrand cross-links. The formation of an interstrand cross-link between the N-7 atoms of two guanine residues at the d(GC) sites was further confirmed by chemical modifications.
一个带有反向SP6和T7启动子的DNA限制片段与顺二氨二氯铂（II）（顺铂）发生反应，然后用作体外RNA合成的模板。T7和SP6 RNA聚合酶产生特定大小的片段。对RNA片段的分析表明，聚合酶主要在d（GG）和d（AG）位点水平受阻，在d（GC）位点水平受阻程度较小。d（GC）位点的加合物比主要位点的加合物对氰离子攻击更具抗性，并且被鉴定为链间交联。通过化学修饰进一步证实了d（GC）位点两个鸟嘌呤残基的N-7原子之间形成链间交联。
