DNA 构象转换促进的平衡链交换。

Equilibrious strand exchange promoted by DNA conformational switching.

机构信息

College of Chemistry and Molecular Sciences, Key Laboratory of Biomedical Polymers of Ministry of Education, Wuhan University, Wuhan, Hubei, P R of China.

出版信息

Sci Rep. 2013;3:1121. doi: 10.1038/srep01121. Epub 2013 Jan 24.

DOI:10.1038/srep01121

PMID:23350029

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC3553462/

Abstract

Most of DNA strand exchange reactions in vitro are based on toehold strategy which is generally nonequilibrium, and intracellular strand exchange mediated by proteins shows little sequence specificity. Herein, a new strand exchange promoted by equilibrious DNA conformational switching is verified. Duplexes containing c-myc sequence which is potentially converted into G-quadruplex are designed in this strategy. The dynamic equilibrium between duplex and G4-DNA is response to the specific exchange of homologous single-stranded DNA (ssDNA). The SER is enzyme free and sequence specific. No ATP is needed and the displaced ssDNAs are identical to the homologous ssDNAs. The SER products and exchange kenetics are analyzed by PAGE and the RecA mediated SER is performed as the contrast. This SER is a new feature of G4-DNAs and a novel strategy to utilize the dynamic equilibrium of DNA conformations.

摘要

大多数体外 DNA 链交换反应都是基于引发链置换的“链侵入”（toehold）策略，这种策略通常是不平衡的，而由蛋白质介导的细胞内链交换几乎没有序列特异性。在此，我们验证了一种由平衡 DNA 构象转换促进的新链交换。在该策略中，设计了含有 c-myc 序列的双链体，该序列可能转化为 G-四链体。双链体和 G4-DNA 之间的动态平衡响应于同源单链 DNA（ssDNA）的特异性交换。SER 是无酶且序列特异性的。不需要 ATP，取代的 ssDNA 与同源 ssDNA 相同。通过 PAGE 分析 SER 产物和交换动力学，并以 RecA 介导的 SER 作为对照。该 SER 是 G4-DNA 的新特征，也是利用 DNA 构象动态平衡的新策略。