通过冷电子显微镜揭示的酶光受体中的信号转导
bioRxiv : the preprint server for biology
|November 21, 2023
概括
这项研究揭示了细菌植物染色体在它们独特的光激活状态中的第一个高分辨率结构. 这些发现揭示了细菌和植物如何感知和响应光信号背后的分子机制.
科学领域:
- 生物化学 生物化学
- 结构生物学 结构生物学
- 微生物学 微生物学
背景情况:
- 植物染色体是植物,细菌和真菌中的关键光受体,通过依赖光的结构变化调节环境反应.
- 它们在红光吸收 (Pr) 和远红光吸收 (Pfr) 状态之间循环,通过像histidine kinase (HK) 这样的酶域影响下游信号通路.
- 尽管有共同的结构元素,但植物和细菌的植物染色体表现出对比的光依赖活动,细菌的植物染色体通常在黑暗中活跃,由于结构数据有限,这一机制不太了解.
研究的目的:
- 通过确定高分辨率结构来阐明细菌植物染色体信号的分子机制.
- 为细菌植物染色体及其相关酶域的独特Pr和Pfr状态提供结构性见解.
- 为了比较细菌和植物植物染色体之间的光信号机制.
主要方法:
- 使用冷电子显微镜 (Cryo-EM) 来确定野生型细菌植物染色体的结构.
- 解决了Pr和Pfr状态的结构,以及一个独特的Pr/Pfr异构体中间体.
- 截断的蛋白质成分的冷EM结构也得到了验证结果.
主要成果:
- 在Pr和Pfr状态下确定了细菌植物染色体 (BphP) 的第一个Cryo-EM结构,其中的histidine kinase (HK) 域在3.75-4.13 Å分辨率下确定.
- 一个新的Pr / Pfr异构体结构,一个潜在的信号传导中间体,在3.75 Å.
- 截断的蛋白质成分的冷电磁结构证实了全长结构,提供了关于信号状态的全面数据.
结论:
- 这些结构为细菌植物染色体的独特光信号机制提供了前所未有的洞察力.
- 这些发现为了解细菌如何感知光线提供了分子基础,与植物植物色素信号形成鲜明对比.
- 这项工作弥合了不同王国中植物色素功能的比较研究中的关键知识差距.
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