杆菌杆菌C终端蛋白酶CtpA的结构揭示了一种新的独立蛋白质分解加工模式
Kailei Sun1, Lili Yan1, Chin Yu Mok1
1Center for Protein Science and Crystallography, School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong, China.
Communications biology
|November 22, 2025
概括
细菌的炭基终端加工蛋白酶 (CTPs) 对于细胞过程至关重要. 这项研究揭示了Helicobacter pylori CtpA如何在它的六边形结构内使用不对称激活来实现适应器独立的蛋白酶功能.
科学领域:
- 生物化学 生化学
- 结构生物学 结构生物学
- 微生物学 微生物学
背景情况:
- 细菌的炭基终端加工蛋白酶 (CTPs) 对蛋白质稳态和细胞信号传递至关重要.
- CTP激活通常依赖于基质结合或适应蛋白,但它们的寡合体多样性和激活机制尚不清楚.
- 细菌物种之间CTP寡合化的结构变化需要详细的机制研究.
研究的目的:
- 阐明来自Helicobacter pylori的六合性碳素终端加工蛋白酶CtpA的激活机制和结构基础.
- 调查寡合组合在调节CTP蛋白解活性中的作用.
- 了解结构动态和相互作用,使基板加工成为可能.
主要方法:
- 生物物理分析包括-交换质谱法 (HDX-MS).
- 电子显微镜 (Cryo-EM) 和X射线晶体学用于结构确定.
- 分析蛋白质-蛋白质相互作用和形状变化.
主要成果:
- 杆菌CtpA形成了一个稳定的二元三元体 (hexameric) 复合体.
- CtpA在休息状态和活跃状态之间经历了基质独立的过渡.
- 在二次体内不对称的形状变化导致了六次体中受调节的蛋白质分解活性.
- 已识别的内部和分子间相互作用稳定功能状态,使适应器独立的激活成为可能.
结论:
- CtpA激活是一个内在的,合作过程,由六体组合内的不对称的形状动态调节.
- 这些发现揭示了蛋白酶激活和过程性基质降解的新机制.
- 这项研究为细菌CTPs的结构可塑性和功能调节提供了关键的见解.
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