Key Lab of Forest Genetics and Biotechnology, Nanjing Forestry University, 159 Longpan Road, Nanjing 210037, China.
Jiangsu Key Laboratory for Biofunctional Molecules, College of Life Science and Chemistry, Jiangsu Second Normal University, Nanjing 210037, China.
Molecules. 2017 Nov 22;22(11):2021. doi: 10.3390/molecules22112021.
Reverse gyrase is a topoisomerase that can introduce positive supercoils to its substrate DNA. It is demonstrated in our studies that a highly thermal stable G-quadruplex structure in a mini-plasmid DNA was transformed into its duplex conformation after a treatment with reverse gyrase. The structural difference of the topoisomers were verified and analyzed by gel electrophoresis, atomic force microscopy examination, and endonuclease digestion assays. All evidence suggested that the overwinding structure of positive supercoil could provide a driven force to disintegrate G-quadruplex and reform duplex. The results of our studies could suggest that hyperthermophiles might use reverse gyrase to manipulate the disintegration of non-B DNA structures and safekeep their genomic information.
反转酶是一种拓扑异构酶，能够将正超螺旋引入其底物 DNA。我们的研究表明，经反转酶处理后，小型质粒 DNA 中的高度热稳定 G-四链体结构转变为双链构象。通过凝胶电泳、原子力显微镜检查和内切酶消化实验验证和分析了拓扑异构体的结构差异。所有证据都表明，正超螺旋的过度缠绕结构可以提供驱动力来破坏 G-四链体并形成双链。我们的研究结果表明，嗜热微生物可能利用反转酶来操纵非 B 型 DNA 结构的解体并保护其基因组信息。
