Institute of Chemical Biology and Fundamental Medicine, Novosibirsk, Russia.
Biochemistry (Mosc). 2009 Nov;74(11):1278-84. doi: 10.1134/s0006297909110157.
The interaction of human recombinant DNA topoisomerase 1 (Top1) with linear and circular DNA structures containing a nick or short gap but lacking a specific Top1 recognition site was studied. The effect of key excision repair proteins on formation of the Top1 covalent adduct with the DNA repair intermediates was shown. Partial inhibition of the Top1-DNA-adduct formation upon addition of poly(ADP-ribose) polymerase 1 in the absence of NAD+ was shown, whereas in the presence of NAD+ formation of a high molecular weight product, most likely corresponding to poly(ADP)-ribosylated Top1-DNA adduct, was observed. The data show that the key base excision repair proteins can influence formation of suicide Top1-DNA adducts. Top1 was identified by immunoprecipitation in the bovine testis nuclear extract as the protein forming the main modification product with nick-containing DNA.
研究了含有切口或短缺口但缺乏特定拓扑异构酶 1（Top1）识别位点的线性和环状 DNA 结构的人重组 DNA Top1（Top1）与线性和环状 DNA 结构的相互作用。显示了关键的切除修复蛋白对 Top1 与 DNA 修复中间体形成共价加合物的影响。当不存在 NAD+时，加入聚（ADP-核糖）聚合酶 1 会部分抑制 Top1-DNA 加合物的形成，而在存在 NAD+的情况下，会形成高分子量产物，很可能对应于聚（ADP）-核糖化的 Top1-DNA 加合物。数据表明，关键的碱基切除修复蛋白可以影响自杀型 Top1-DNA 加合物的形成。通过免疫沉淀法在牛睾丸核提取物中鉴定出 Top1 是与含切口 DNA 形成主要修饰产物的蛋白质。
