血溶素A分泌系统是一个多发动机,包含三个ABC输送器
Hongtu Zhao1, James Lee2, Jue Chen2
1Laboratory of Membrane Biology and Biophysics, The Rockefeller University, New York, NY 10065, USA.
Cell
|September 2, 2022
概括
1型分泌系统 (T1SS) 使用三种蛋白质输出基质. 化EM检测显示了细菌蛋白质分泌所必需的异体体内膜复合体.
科学领域:
- 微生物学
- 结构生物学
- 生物化学
背景情况:
- 1型分泌系统 (T1SS) 对于格拉姆阴性细菌的蛋白质输出至关重要.
- 大肠杆菌的血溶素A分泌系统是研究得很好的T1SS原型.
- T1SS包括一个内膜ABC输送器,一个适应蛋白和一个外膜孔.
研究的目的:
- 阐明T1SS内膜复合体的结构和静态度.
- 通过T1SS了解蛋白质转移的机制.
主要方法:
- 低温电子显微镜 (cryo-EM) 用于确定高分辨率结构.
- 功能测试以评估蛋白质寡合化在分泌中的作用.
主要成果:
- 内膜复合体是一个由3个HlyB同位体和6个HlyD子单元组成的异位体.
- HlyB和HlyD的寡合化对于有效的蛋白质分泌至关重要.
- 多转移通过HlyB ABC输送器发生.
结论:
- T1SS使用涉及ABC载体的多子单元复合体进行蛋白质分泌.
- 该结构揭示了一种涉及多个ABC输送器在基质转移中的新机制.
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