Reparative helicase II of Deinococcus radiodurans performs an unexpected critical function in repair of double-strand DNA breaks through the mechanism of extended synthesis-dependent strand annealing (ESDSA), while it is considered as an optional participant in the RecF pathway of recombinational repair in Escherichia coli. A fragment of genomic DNA of the radioresistant bacterium Deinococcus radiodurans with the uvrD gene encoding DNA helicase II, which is involved in excision repair of nucleotides, mismatch repair, and recombinational repair and replication, was cloned in the cells of the model object, Escherichia coli K-12. The pCR 2.1-uvrD+ plasmid restores resistance to ultraviolet light of mutant cells of Escherichia coliuvrD–, helD–, and rep– defective in reparative helicase II, helicase IV, and replicative helicase Rep, respectively, almost to the level of wild-type AB1157 and uvrD+, and, to a lesser extent, the strain with a mutation in the recQ gene encoding the key helicase of recombinational repair RecQ. The protective effect is also noticeable when strains with the plasmid are irradiated with γ-rays. It is established that Deinococcus radiodurans UvrD helicase possesses broad possibilities.

中文翻译：

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耐辐射奇异球菌R1 uvrD基因编码的DNA解旋酶在大肠杆菌K-12细胞中的特征

耐辐射奇异球菌的修复解旋酶 II 通过扩展合成依赖性链退火 (ESDSA) 机制在修复双链 DNA 断裂方面发挥出乎意料的关键功能，同时它被认为是埃希氏菌重组修复 RecF 途径的可选参与者大肠杆菌。耐辐射细菌耐辐射奇异球菌的基因组 DNA 片段，其 uvrD 基因编码 DNA 解旋酶 II，参与核苷酸切除修复、错配修复、重组修复和复制，被克隆到模型对象大肠杆菌的细胞中K-12。pCR 2.1-uvrD+ 质粒恢复了分别在修复性解旋酶 II、解旋酶 IV 和复制性解旋酶 Rep 中缺陷的大肠杆菌突变细胞对紫外线的抗性。几乎达到野生型 AB1157 和 uvrD+ 的水平，并且在较小程度上，编码重组修复 RecQ 关键解旋酶的 recQ 基因发生突变的菌株。当用 γ 射线照射带有质粒的菌株时，保护作用也很明显。确定耐辐射奇异球菌 UvrD 解旋酶具有广泛的可能性。