Lindsley J E, Cox M M
Department of Biochemistry, College of Agricultural and Life Sciences, University of Wisconsin, Madison 53706.
J Biol Chem. 1990 Jun 5;265(16):9043-54.
RecA protein primarily associates with and dissociates from opposite ends of nucleoprotein filaments formed on linear duplex DNA. RecA nucleoprotein filaments that are hydrolyzing ATP therefore engage in a dynamic process under some conditions that has some of the properties of treadmilling. We have also investigated whether the net polymerization of recA protein at one end of the filament and/or a net depolymerization at the other end drives unidirectional strand exchange. There is no demonstrable correlation between recA protein association/dissociation and the strand exchange reaction. RecA protein-mediated DNA strand exchange is affected minimally by changes in reaction conditions (dilution, pH shift, or addition of small amounts of adenosine-5'-O-(3-thiotriphosphate) that have large and demonstrable effects on recA protein association, dissociation, or both. Rather than driving strand exchange, these assembly and disassembly processes may simply represent the mechanism by which recA nucleoprotein filaments are recycled in the cell.
RecA蛋白主要与线性双链DNA上形成的核蛋白丝的两端结合并解离。因此，正在水解ATP的RecA核蛋白丝在某些条件下会参与一个具有一些踏车行为特性的动态过程。我们还研究了RecA蛋白在丝的一端的净聚合和/或另一端的净解聚是否驱动单向链交换。RecA蛋白的结合/解离与链交换反应之间没有明显的相关性。RecA蛋白介导的DNA链交换受反应条件变化（稀释、pH值变化或添加少量腺苷-5'-O-(3-硫代三磷酸)）的影响最小，而这些变化对RecA蛋白的结合、解离或两者都有显著影响。这些组装和解聚过程可能并非驱动链交换，而仅仅代表了RecA核蛋白丝在细胞中循环利用的机制。
