Probing Molecular Interactions During RecA-Mediated DNA Strand Exchange Using Nucleotide Analogs

莱斯大学化学系的启动基金支持斯科特·f·辛格尔顿教授的研究。本研究的重点是对大肠杆菌核酸重组酶RecA蛋白介导的链交换过程的分子理解。这项工作基于化学动力学研究，例如，核苷酸修饰对动力学参数的影响，为链交换过程制定了特定的结构和机制模型。瞬态和稳态动力学实验使用含有核苷酸类似物的DNA链进行，这些类似物在底物、产物和中间物质的稳定性和构象中引入保守的变化。结果可以表征与交换过程中每个可识别步骤相关的动力学和热力学参数与参与DNA分子的物理化学性质之间的关系。该研究促进了对同源基因重组的分子水平理解，同源基因重组是DNA修复、复制、调控和分化的重要生物学过程。

This starter grant award of the Chemistry Division to Rice University supports the research of Professor Scott F. Singleton. The research focuses on a molecular understanding of the strand exchange process mediated by the RecA protein of Escherichia coli, a nucleic acid recombinase. The work formulates specific structural and mechanistic models for the strand exchange process based on chemical kinetic investigations into, for example, the influence of nucleotide modifications on the kinetic parameters. Transient and steady-state kinetic experiments are performed using DNA strands which contain nucleotide analogs that introduce conservative changes in the stabilities and conformations of the substrate, product, and intermediate species. The results allow characterization of the relationships between the kinetic and thermodynamic parameters associated with each identifiable step in the exchange process and the physicochemical properties of the participating DNA molecules. The research advances the a molecular level understanding of homologous genetic recombination, a biological process important in DNA repair, replication, regulation, and differentiation.