Unit of Polar Genomics, Korea Polar Research Institute, Incheon, 21990, Republic of Korea.
Unit of Polar Genomics, Korea Polar Research Institute, Incheon, 21990, Republic of Korea; Department of Polar Sciences, University of Science and Technology, Incheon, 21990, Republic of Korea.
Biochem Biophys Res Commun. 2019 May 28;513(2):374-379. doi: 10.1016/j.bbrc.2019.04.019. Epub 2019 Apr 6.
In cold and harsh environments such as glaciers and sediments in ice cores, microbes can survive by forming spores. Spores are composed of a thick coat protein, which protects against external factors such as heat-shock, high salinity, and nutrient deficiency. GerE is a key transcription factor involved in spore coat protein expression in the mother cell during sporulation. GerE regulates transcription during the late sporulation stage by directly binding to the promoter of cotB gene. Here, we report the crystal structure of PaGerE at 2.09 Å resolution from Paenisporosarcina sp. TG-14, which was isolated from the Taylor glacier. The PaGerE structure is composed of four α-helices and adopts a helix-turn-helix architecture with 68 amino acid residues. Based on our DNA binding analysis, the PaGerE binds to the promoter region of CotB to affect protein expression. Additionally, our structural comparison studies suggest that DNA binding by PaGerE causes a conformational change in the α4-helix region, which may strongly induce dimerization of PaGerE.
在冰川和冰芯沉积物等寒冷恶劣的环境中，微生物可以通过形成孢子来生存。孢子由一层厚厚的外壳蛋白组成，可保护其免受热冲击、高盐度和营养缺乏等外部因素的影响。GerE 是孢子外壳蛋白表达过程中母细胞中涉及的关键转录因子。GerE 通过直接与 cotB 基因的启动子结合，在晚期孢子形成阶段调节转录。在这里，我们报道了来自于 Paenisporosarcina sp. TG-14 的 PaGerE 的晶体结构，该结构是在泰勒冰川中分离出来的。PaGerE 结构由四个α-螺旋组成，采用具有 68 个氨基酸残基的螺旋-转角-螺旋结构。基于我们的 DNA 结合分析，PaGerE 结合到 CotB 的启动子区域以影响蛋白表达。此外，我们的结构比较研究表明，PaGerE 通过 DNA 结合导致α4-螺旋区域的构象变化，这可能会强烈诱导 PaGerE 的二聚化。
