从原始时钟到昼夜振荡器
Warintra Pitsawong1,2, Ricardo A P Pádua1, Timothy Grant3,4,5
1Howard Hughes Medical Institute and Department of Biochemistry, Brandeis University, Waltham, MA, USA.
Nature
|March 23, 2023
概括
这项研究揭示了Rhodobacter sphaeroides古老的KaiBC昼夜时钟机制,确定ATP与ADP的比率是驱动这种原始生物时钟的关键环境提示.
科学领域:
- 生物化学
- 分子生物学
- 时间生物学
背景情况:
- 循环节律是通过后翻译振荡器调节的基本生物过程.
- KaiABC 系统是已知的蓝藻生物的昼夜时钟,但古老的 KaiBC 系统在很大程度上仍未被描述.
- 据推测,这些KaiBC系统具有类似于沙表的基本计时机制.
研究的目的:
- 研究 Rhodobacter sphaeroides 的原始昼夜时钟,该时钟仅使用 KaiBC 蛋白质.
- 为了阐明这个古老的计时系统的分子机制,
- 了解昼夜振荡器的演化起源.
主要方法:
- 使用X射线结晶学和冷电子显微镜来确定KaiC的结构.
- 进行了动态分析以识别环境线索并了解时钟动态.
- 整合了结构和运动数据,以绘制KaiC蛋白内的全网络.
主要成果:
- 发现了 KaiC 的一种新型 dodecameric 折叠,由两个由 12 螺旋线圈捆绑连接的六合体组成.
- 这种由KaiC carboxy终端延伸介导的线圈-线圈相互作用代表了一个古老的调节元件.
- 确定了连接形状变化到化位点的远程化网络.
- 发现ATP与ADP的比率是驱动时钟每日循环的环境信号.
结论:
- 在Rhodobacter sphaeroides中,KaiBC系统作为一个原始的昼夜振荡器.
- 已识别的十二度 KaiC 结构及其全调节为生物钟的演变提供了洞察力.
- 环境的ATP-ADP波动是这个古老的生物钟背后的驱动力,
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