STATISTICAL-MECHANICS OF SUPERCOILED DNA
STATISTICAL-MECHANICS OF SUPERCOILED DNA
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DOI：
10.1103/physreve.52.2912
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发表时间：
1995-09-01
影响因子：
2.4
通讯作者：
SIGGIA, ED
中科院分区：
文献类型：
--
作者：
MARKO, JF;SIGGIA, ED
闭合环状DNA分子的两条链具有它们的连接数作为拓扑不变量。这种性质，加上一个可观的扭曲弹性常数，导致双螺旋在施加非平衡扭曲时在空间中呈现超螺旋构象。热涨落在确定超螺旋的构象中起着至关重要的作用，它设定了一个定义明确的相互缠绕的超螺旋形成的连接数标度。除了平衡超螺旋结构，我们讨论超螺旋弯曲和分支，并显示如何在大规模超螺旋DNA成为一个分支聚合物。还推导了螺旋内螺旋反应发生所需的特征时间和延伸扭曲DNA所需的力。
The two strands of a closed circular DNA molecule possess as a topological invariant their linking number. This property, combined with an appreciable twist elastic constant, causes the double helix to assume a supercoiled conformation in space when a nonequilibrium twist is imposed. Thermal fluctuations play a crucial role in determining the conformation of supercoils, setting the linking number scale at which a well-defined interwound supercoil forms. In addition to equilibrium supercoil structure, we discuss supercoil bending and branching and show how at large scales supercoiled DNA becomes a branched polymer. The characteristic time required for intrasupercoil reactions to occur and the force necessary to extend twisted DNA are also derived.