DNA STRUCTURES WHICH STIMULATE GENETIC RECOMBINATION

刺激基因重组的DNA结构的性质 （重组结构）的分子过程，涉及这些 结构，以及介导这些过程的蛋白质，将被 表征了 大多数实验采用DNA λ复制技术， 重组和DNA修复系统。 生物 用于重组和DNA修复的生物化学（转染）测定，以及用于重组和DNA修复的生物化学（转染）测定。 将使用用于重组的限制性内切酶（限制性-电泳）测定。 的 E. coliarl基因的结构 在arl-突变体上生长的噬菌体DNA中的单链样区域， 这些“Arl-”损伤刺激重组的机制将是 阐明。 紫外线照射DNA中的重组光产物将 确定，和重组结构所产生的修复 紫外线损伤的DNA和尿嘧啶DNA的特点。 无细胞系统， 基于UV-DNA的修复重组，将用于确定 DNA促旋酶和Rec A蛋白的生化作用。 的新技术 获得新的E. coli“hyper-rec”突变体。 生化 对噬菌体λ“Red”重组系统的分析将被照射。

The nature of DNA structures which stimulate genetic recombination (recombinogenic structures), of the molecular processes which involve these structures, and of the proteins which mediate these processes, are to be characterized. Most experiments employ DNA lambda duplication phages and the recombination and DNA repair systems of Escherichia coli. A biological (transfection) assay for recombination and DNA repair, and a biochemical (restriction-electrophoresis) assay for recombination will be used. The identity of the product of the E. coli arl gene, the structure of the single-strand-like regions in DNA of phage grown on arl-mutants, and the mechanism by which these "Arl-" lesions stimulate recombination are to be elucidated. The recombinogenic photoproducts in UV-irradiated DNA will be determined, and the recombinogenic structures resulting from repair of UV-damaged DNA and uracil-containing DNA characterized. Cell-free systems, based on repair-recombination of UV-DNA, will be used to determine the biochemical roles of DNA gyrase and the Rec A protein. A novel technique for obtaining new classes of E. coli "hyper-rec" mutants is proposed. Biochemical analysis of the phage lambda "Red" recombination system will be irradiated.