Research Institute of Agriculture and Life Sciences, Center for Food and Bioconvergence, Department of Agricultural Biotechnology, CALS, Seoul National University, Seoul, 08826, Republic of Korea.
Current address: KoBioLabs, Inc., Seoul, 08826, Republic of Korea.
J Microbiol. 2021 Jun;59(6):584-589. doi: 10.1007/s12275-021-1012-0. Epub 2021 Apr 20.
The SbcCD complex is an essential component of the DNA double-strand break (DSB) repair system in bacteria. The bacterial SbcCD complex recognizes and cleaves the DNA ends in DSBs by ATP-dependent endo- and exonuclease activities as an early step of the DNA repair process. SbcD consists of nuclease, capping, and helix-loop-helix domains. Here, we present the crystal structure of a SbcD fragment from Staphylococcus aureus, which contained nuclease and capping domains, at a resolution of 2.9 Å. This structure shows a dimeric assembly similar to that of the corresponding domains of SbcD from Escherichia coli. The S. aureus SbcD fragment exhibited endonuclease activities on supercoiled DNA and exonuclease activity on linear and nicked DNA. This study contributes to the understanding of the molecular basis for how bacteria can resist sterilizing treatment, causing DNA damage.
SbcCD 复合物是细菌中 DNA 双链断裂 (DSB) 修复系统的必需组成部分。细菌 SbcCD 复合物通过 ATP 依赖性内切核酸酶和外切核酸酶活性识别和切割 DSB 中的 DNA 末端，作为 DNA 修复过程的早期步骤。SbcD 由核酸酶、加帽和螺旋-环-螺旋结构域组成。在这里，我们呈现了来自金黄色葡萄球菌的 SbcD 片段的晶体结构，分辨率为 2.9 Å。该结构显示出类似于大肠杆菌 SbcD 相应结构域的二聚体组装。金黄色葡萄球菌 SbcD 片段在超螺旋 DNA 上表现出内切核酸酶活性，在线性和缺口 DNA 上表现出外切核酸酶活性。这项研究有助于理解细菌如何抵抗杀菌处理并导致 DNA 损伤的分子基础。
