核酸结合蛋白 Sac10b 中的双维相互作用导致双链DNA 的多重桥接
Songqiang Tang1, Chun-Hsiang Huang2, Tzu-Ping Ko3
1State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, 430062, China.
Heliyon
|June 13, 2024
概括
来自Sulfolobus acidocaldarius的核素相关蛋白 Sac10b1和Sac10b2通过不同的桥梁机制来组织DNA. 这些热稳定蛋白质对于极端环境中的遗传物质稳定性至关重要.
科学领域:
- 微生物学 微生物学
- 结构生物学 结构生物学
- 生物化学 生物化学
背景情况:
- 核素相关蛋白 (NAP) 是所有生物体中DNA紧缩和调节的重要组成部分.
- 萨克10b家族 (阿尔巴蛋白) 是在古生物中发现的高度保存的NAP,包括热酸性 Sulfolobus acidocaldarius.
- Sac10b代表了S.acidocaldarius.中第一个确定的10kDa的DNA结合蛋白.
研究的目的:
- 从S.acidocaldarius.确定Sac10b1和Sac10b2的晶体结构.
- 调查Sac10b1和Sac10b2.2的DNA结合和桥接能力.
- 通过Sac10b1.1.阐明合作性DNA结合和丝形成的结构基础.
主要方法:
- 进行X射线晶体学以确定Sac10b1,Sac10b2和Sac10b1突变体 (F59A) 的高分辨率结构 (1.4-2.0 Å).
- 电子显微镜可视化蛋白质的DNA桥接活动.
- 分析超离心和循环二元化,以评估蛋白质的热稳定性和酸耐受性.
主要成果:
- 晶体结构揭示了Sac10b1和Sac10b2.2的分子结构.
- 电子显微镜证明了DNA桥接能力,Sac10b1显示了比Sac10b2.2更广泛的桥接.
- Sac10b1促进合作性DNA结合,并通过在二次体-二次体界面上的保存残留物 (R58,F59) 形成桥梁纤维;在这些位点的突变减少了合作性结合和纤维形成,模仿Sac10b2的行为.
- 这两种蛋白质都形成稳定,热稳定和耐酸二极体.
结论:
- 在古生物中,Sac10b蛋白质在组织和稳定染色体DNA方面发挥着至关重要的作用.
- 由Sac10b1和Sac10b2介导的明显的桥接相互作用有助于DNA组织,特别是在极端的环境条件下.
- 保存的残留物R58和F59对于Sac10b1的合作DNA结合和线程形成至关重要.
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