Charvin G, Strick T R, Bensimon D, Croquette V
LPS, ENS, UMR 8550 CNRS, 75231 Paris Cedex 05, France.
Annu Rev Biophys Biomol Struct. 2005;34:201-19. doi: 10.1146/annurev.biophys.34.040204.144433.
The recent development of new techniques to manipulate single DNA molecules has opened new opportunities for the study of the enzymes that control DNA topology: the type I and II topoisomerases. These single-molecule assays provide a unique way to study the uncoiling of single supercoiled DNA molecules and the unlinking of two intertwined DNAs. They allow for a detailed characterization of the activity of topoisomerases, including the processivity, the chiral discrimination, and the dependence of their enzymatic rate on ATP concentration, degree of supercoiling, and the tension in the molecule. These results shed new light on the mechanism of these enzymes and their function in vivo.
操纵单个DNA分子的新技术的最新发展为研究控制DNA拓扑结构的酶——I型和II型拓扑异构酶，带来了新的机遇。这些单分子检测方法为研究单个超螺旋DNA分子的解旋以及两条相互缠绕的DNA的解链提供了独特的途径。它们能够对拓扑异构酶的活性进行详细表征，包括持续性、手性识别以及其酶促速率对ATP浓度、超螺旋程度和分子张力的依赖性。这些结果为这些酶的作用机制及其在体内的功能提供了新的线索。
