Several species of Sulfolobales have been used as model organisms in the study of response mechanisms to ultraviolet (UV) irradiation in hyperthermophilic crenarchaea. To date, the transcriptional responses of genes involved in the initiation of DNA replication, transcriptional regulation, protein phosphorylation, and hypothetical function have been observed in Sulfolobales species after UV irradiation. However, due to the absence of knockout experiments, the functions of these genes under in situ UV irradiation have not yet been demonstrated. In the present study, we constructed five gene knockout strains (cdc6-2, tfb3, rio1, and two genes encoding the hypothetical proteins, Saci_0951 and Saci_1302) of Sulfolobus acidocaldarius and examined their sensitivities to UV irradiation. The knockout strains exhibited significant sensitivities to UV-B irradiation, indicating that the five UV-regulated genes play an important role in responses to UV irradiation in vivo. Furthermore, Δcdc6-2, Δrio1, ΔSaci_0951, and Δtfb3 were sensitive to a wide variety of helix-distorting DNA lesions, including UV-induced DNA damage, an intra-strand crosslink, and bulky adducts. These results reveal that cdc6-2, tfb3, rio1, and Saci_0951 are play more important roles in broad responses to helix-distorting DNA damage than in specific responses to UV irradiation.

中文翻译：

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紫外线调节基因参与嗜热酸热硫化叶菌螺旋扭曲 DNA 损伤的反应


一些硫化叶菌属物种已被用作模型生物，研究超嗜热龟裂菌对紫外线 (UV) 照射的反应机制。迄今为止，在紫外线照射后，已在硫化叶菌属物种中观察到涉及 DNA 复制起始、转录调控、蛋白质磷酸化和假设功能的基因的转录反应。然而，由于缺乏敲除实验，这些基因在原位紫外线照射下的功能尚未得到证实。在本研究中，我们构建了酸热硫化叶菌的 5 个基因敲除菌株（cdc6-2、tfb3、rio1 和编码假设蛋白 Saci_0951 和 Saci_1302 的两个基因），并检查了它们对紫外线照射的敏感性。敲除菌株对 UV-B 照射表现出显着的敏感性，表明 5 个 UV 调节基因在体内对 UV 照射的反应中发挥着重要作用。此外，Δcdc6-2、Δrio1、ΔSaci_0951 和 Δtfb3 对多种螺旋扭曲 DNA 损伤敏感，包括紫外线诱导的 DNA 损伤、链内交联和大体积加合物。这些结果表明，cdc6-2、tfb3、rio1 和 Saci_0951 在对螺旋扭曲 DNA 损伤的广泛反应中比在对紫外线照射的特定反应中发挥更重要的作用。