Rosselli W, Stasiak A
Laboratoire d'Analyse Ultrastructurale, Université de Lausanne, Switzerland.
J Mol Biol. 1990 Nov 20;216(2):335-52. doi: 10.1016/S0022-2836(05)80325-0.
We demonstrate that the step of DNA strand exchange during RecA-mediated recombination reaction can occur equally efficiently in the presence or absence of ATP hydrolysis. The polarity of strand exchange is the same when instead of ATP its non-hydrolyzable analog adenosine-5'-O-(3-thiotriphosphate) is used. We show that the ATP dependence of recombination reaction is limited to the post-exchange stages of the reactions. The low DNA affinity state of RecA protomers, induced after ATP hydrolysis, is necessary for the dissociation of RecA-DNA complexes at the end of the reaction. This dissociation of RecA from DNA is necessary for the release of recombinant DNA molecules from the complexes formed with RecA and for the recycling of RecA protomers for another round of the recombination reaction.
我们证明，在RecA介导的重组反应中，DNA链交换步骤在有或没有ATP水解的情况下都能同样高效地发生。当使用ATP的非水解类似物腺苷-5'-O-(3-硫代三磷酸)代替ATP时，链交换的极性是相同的。我们表明，重组反应对ATP的依赖性仅限于反应的交换后阶段。ATP水解后诱导的RecA原聚体的低DNA亲和力状态对于反应结束时RecA-DNA复合物的解离是必要的。RecA从DNA上的这种解离对于从与RecA形成的复合物中释放重组DNA分子以及RecA原聚体循环用于另一轮重组反应是必要的。
