Structural and biochemical impact of C8-aryl-guanine adducts within the NarI recognition DNA sequence: influence of aryl ring size on targeted and semi-targeted mutagenicity
作者:Michael Sproviero、Anne M.R. Verwey、Katherine M. Rankin、Aaron A. Witham、Dmitriy V. Soldatov、Richard A. Manderville、Mostafa I. Fekry、Shana J. Sturla、Purshotam Sharma、Stacey D. Wetmore
DOI:10.1093/nar/gku1093
日期:2014.12.1
Chemical mutagens with an aromaticringsystem may be enzymatically transformed to afford aryl radical species that preferentially react at the C8-site of 2'-deoxyguanosine (dG). The resulting carbon-linked C8-aryl-dG adduct possesses altered biophysical and genetic coding properties compared to the precursor nucleoside. Described herein are structural and in vitro mutagenicity studies of a series
具有芳香环系统的化学诱变剂可以被酶促转化,以提供优先在2'-脱氧鸟苷(dG)的C8位反应的芳基基团。与前体核苷相比,所得的碳连接的C8-芳基-dG加合物具有改变的生物物理和遗传编码特性。本文描述了一系列荧光C8-芳基-dG类似物的结构和体外诱变性研究,这些类似物的芳基环大小不同,代表了真实的DNA加合物。这些结构模拟物已插入到移码突变的热点序列中,即在12mer(NarI(12))和22mer(NarI(22))寡核苷酸内NarI序列的重复G3位置。在NarI(12)双链体中,C8-芳基-dG加合物显示出偏好采用与C相反的反构象,尽管对游离核苷有强烈的顺式偏爱。使用NarI(22)序列作为体外DNA合成的模板,使用代表性的高保真复制性和病灶旁路Y家族DNA聚合酶,即大肠杆菌pol I Klenow片段,分析了C8-芳基-dG加合物的致突变性exo(-)(Kf(-))和Sulfolobus solfataricus