DNA STRUCTURES WHICH STIMULATE GENETIC RECOMBINATION

刺激基因重组的DNA结构的本质 (重组结构)，涉及这些的分子过程 结构，以及中介这些过程的蛋白质，将是 特色化的。大多数实验使用DNA lambda复制噬菌体和 大肠杆菌的重组和DNA修复系统。一种生物学的 (转染法)重组和DNA修复试验，以及一种生化 重组将采用(限制性-电泳法)分析。这个 大肠杆菌ARL基因产物的鉴定、结构分析 在ARL突变体上生长的噬菌体DNA中的单链样区，以及 这些“ARL-”损伤刺激重组的机制是 已澄清。经紫外线照射的DNA中的重组光产物将是 确定的，以及由修复所产生的重组结构 对紫外线损伤的DNA和含有尿嘧啶的DNA进行了表征。无牢房系统， 基于UV-DNA的修复-重组，将被用于确定 DNA旋转酶和Rec A蛋白的生化作用。一种新的治疗技术 提出了获得新的大肠杆菌“高重组”突变体的建议。生化 分析噬菌体Lambda“Red”重组系统是否会受到辐射。

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.