Hays J B, Martin S J, Bhatia K
J Bacteriol. 1985 Feb;161(2):602-8. doi: 10.1128/jb.161.2.602-608.1985.
The system previously used to study recombination of nonreplicating UV-irradiated phage lambda DNA was adapted to study UV repair. Irradiated phages infected undamaged homoimmune lysogens. Pyrimidine dimer content (by treatment with Micrococcus luteus UV endonuclease and alkaline sucrose sedimentation) and a biological activity endpoint (infectivity in transfection of uvrB recA recB spheroplasts) were followed. Unless room light was excluded during DNA extraction procedures, photoreactivation (Phr function) was significant. In uvr delta phr bacteria, repair, by both assays, was very low but not zero. Even when light was totally excluded, Phr function appeared to play a role in Uvr-mediated excision repair: both dimer removal and restoration of infectivity were two to five times as efficient in uvr+ phr+ bacteria as in uvr+ delta phr bacteria. Similarly, UV-irradiated phages plated with higher efficiencies on phr+ than delta phr bacteria even under totally dark conditions. In uvr phr+ repressed infections, removal of dimers from nonreplicating DNA did not increase infectivity as much as in uvr+ infections, suggesting a requirement for repair of nondimer photoproducts by the uvrABC system.
先前用于研究非复制型紫外线照射的噬菌体λDNA重组的系统被用于研究紫外线修复。用经紫外线照射的噬菌体感染未受损的同免疫溶原菌。跟踪嘧啶二聚体含量（通过用藤黄微球菌紫外线内切核酸酶处理和碱性蔗糖沉降法）和一个生物学活性终点（在uvrB recA recB原生质球转染中的感染性）。除非在DNA提取过程中排除室内光线，否则光复活（Phr功能）很显著。在uvrΔphr细菌中，通过两种测定方法检测到的修复率都非常低但不为零。即使完全排除光线，Phr功能似乎在Uvr介导的切除修复中发挥作用：uvr⁺phr⁺细菌中去除二聚体和恢复感染性的效率是uvr⁺Δphr细菌中的两到五倍。同样，即使在完全黑暗的条件下，紫外线照射的噬菌体在phr⁺细菌上的铺板效率也高于Δphr细菌。在uvr phr⁺抑制感染中，从非复制型DNA中去除二聚体并没有像在uvr⁺感染中那样显著增加感染性，这表明uvrABC系统需要修复非二聚体光产物。
