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来自Methanocaldococcus jannaschiichii的一个16.5kDa小热冲击蛋白的冷EM结构

Joohyun Lee¹, Bumhan Ryu², Truc Kim¹

¹Department of Precision Medicine, Graduate School of Basic Medical Science (GSBMS), Institute for Antimicrobial Resistance Research and Therapeutics, Sungkyunkwan University School of Medicine, Suwon 16419, Republic of Korea.

International journal of biological macromolecules

|December 16, 2023

概括

小热冲击蛋白 (sHSP) MjsHSP16.5 的冷-EM 结构显示其 N-终端域处于不那么紧的状态,类似于其原生形式. 这一发现澄清了sHSP的结构和功能,并有潜在的应用作为纳米级蛋白质平台.

科学领域:

结构生物学是结构生物学.
生物化学生物化学
考古学研究考古学研究.

背景情况:

小热冲击蛋白 (sHSPs) 是ATP独立的伴侣,对于压力下的蛋白质平衡至关重要.
来自Methanocaldococcus jannaschii的MjsHSP16.5是一种经过充分研究的sHSP,值得注意的是,它是第一个通过X射线晶体学进行特征的.
尽管进行了广泛的研究,但MjsHSP16.5中的N端域 (NTD) 的精确排列仍然不清楚.

研究的目的:

为了确定MjsHSP16.5.5.的高分辨率冷电子显微镜 (cryo-EM) 结构.
为了阐明MjsHSP16.5寡合体内NTDs的排列.
了解 NTD 结构对 sHSP 函数和原始状态相似性的影响.

主要方法:

低温电子显微镜 (cryo-EM) 用于以2.49-Å分辨率解析MjsHSP16.5结构.
结构分析比较冷电磁和晶体结构.
使用Cys替代突变体进行二硫化键交叉链接研究.
蛋白质分解试验. 蛋白质分解试验.
结构预测分析.

主要成果:

化EM结构显示MjsHSP16.5的子单元与晶体结构相比,紧缩性较低,表明状态更接近原生构造.
在NTD中观察到残留物的密度为24-33,在晶体结构中通常是无序的.
这些NTD残留物采用β-链形态,并与链β1相互作用,无论是分子内还是分子间.
结构发现得到了交叉链接数据,结构预测和功能分类测试的支持.

结论:

冷-EM结构提供了更准确的MjsHSP16.5的本土状态的表现,澄清了NTD在其护送机制中的作用.
观察到的NTD相互作用会影响整体四级结构和潜在的基质结合和释放动态.
了解MjsHSP16.5的结构可塑性和NTD行为可以指导开发利用sHSP作为多功能纳米级平台的新型应用程序.

关键词:

化电磁波是一种冷电磁波.甲热球菌 (Methanocaldococcus jannaschiichii) 是一种有毒的植物.分子的伴侣是分子的伴侣.N-终端域域名是一个N-终端域名.蛋白质聚合蛋白质的聚合.小热冲击蛋白质是一种小热冲击蛋白质.

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