标题：Knockouts of RecA-Like Proteins RadC1 and RadC2 Have Distinct Responses to DNA Damage Agents in Sulfolobus islandicus
作者：Peng-Juan Liang;Wen-Yuan Han;Qi-Hong Huang;Yan-Ze Li;Jin-Feng Ni;Qun-Xin She;Yu-Long Shen
作者机构：[Liang, P.-J] State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, China;[ Han, W.-Y] State Key Laboratory of Microbial Te 更多
通讯作者地址：[Shen, YL]Shandong Univ, State Key Lab Microbial Technol, Jinan 250100, Peoples R China.
关键词：RecA-like protein;RadA;RadC;Sulfolobus;DNA repair
摘要：RecA family recombinases play essential roles in maintaining genome integrity. A group of RecA-like proteins named RadC are present in all archaea, but their in vivo functions remain unclear. In this study, we performed phylogenetic and genetic analysis of two RadC proteins from Sulfolobus islandicus. RadC is closer to the KaiC lineage of cyanobacteria and proteobacteria than to the lineage of the recombinases (RecA, RadA, and Rad51) and the recombinase paralogs (e.g., RadB, Rad55, and Rad51B). Using the recently-stablished S. islandicus genetic system, we constructed deletion and over-expression strains of radC1 and radC2. Deletion of radC1 rendered the cells more sensitive to DNA damaging agents, methyl methanesulfonate (MMS), hydroxyurea (HU), and ultraviolet (UV) radiation, than the wild type, and a Delta radC1 Delta radC2 double deletion strain was more sensitive to cisplatin and MMS than the Delta radC1 single deletion mutant. In addition, ectopic expression of His-tagged RadC1 revealed that RadC1 was co-purified with a putative structure-specific nuclease and ATPase, which is highly conserved in archaea. Our results indicate that both RadC1 and RadC2 are involved in DNA repair. RadC1 may play a general or primary role in DNA repair, while RadC2 plays a role in DNA repair in response to specific DNA damages.