货物运输车辆VI型分泌系统的结构和组装
Wenbo He1, Ke Wu2, Zhenlin Ouyang1
1Center for Microbiome Research of Med-X Institute, Shaanxi Provincial Key Laboratory of Sepsis in Critical Care Medicine, The First Affiliated Hospital, Xi'an Jiaotong University, Xi'an 710061, China.
Cell reports
|July 8, 2023
概括
第六类分泌系统 (T6SS) 的结构使用冷EM和晶体结构来确定. 这揭示了细菌T6SS纳米机器如何组装和燃烧以调解细胞竞争和宿主相互作用.
科学领域:
- 微生物学 微生物学
- 结构生物学 结构生物学
- 分子生物学分子生物学
背景情况:
- 六型分泌系统 (T6SS) 是格拉姆阴性细菌中至关重要的纳米机器.
- 它调解了有毒效应物的注射到细胞中,影响了细菌的竞争和宿主相互作用.
- 像Hcp,VgrG和PAAR这样的关键组件参与了效应器加载和输送.
研究的目的:
- 为了阐明T6SS Hcp5-VgrG-PAAR复合物的结构基础.
- 了解效应器加载和T6SS组装和发射的机制.
主要方法:
- 完整的T6SS复合体的2.8 Å分辨率的冷电子显微镜 (冷电子显微镜).
- 来自*B. fragilis*的未结合的Hcp5的X射线晶体学NCTC 9343.
主要成果:
- 确定了完整的T6SS Hcp5-VgrG-PAAR货物输送系统的冷电磁结构.
- 揭示了Hcp5对VgrG的六边形环负荷扩大了其腔,调节了聚合和外动态.
- 确定了VgrG三合体和Hcp六合体之间的不对称相互作用,包括Hcp单体中的循环翻转.
- 在Hcp和VgrG之间证明了高亲和度的结合,涉及向不利的循环结构.
结论:
- 这项研究为T6SS纳米机器的组装,加载和发射机制提供了原子层面的见解.
- 了解这些过程对于理解细菌的物种间竞争和宿主-病原体相互作用至关重要.
相关概念视频
Clathrin Coated Vesicles
7.1K
Clathrin-coated vesicles use endocytosis to transport receptors and lysosomal hydrolases from the Golgi to the lysosome in the late secretory pathway. Clathrin-mediated endocytosis was the first described endocytic process, and Clathrin-coated vesicles remain one of the most well-studied transport vesicles. The molecular machinery that generates clathrin-coated vesicles comprises over 50 proteins that precisely coordinate vesicle formation. Cell surface receptors concentrated in indented sites...
7.1K
Gram-negative Bacterial Protein Secretion Systems
49
Gram-negative bacteria utilize sophisticated protein secretion systems to transport proteins across their double-membrane envelope into the extracellular environment or host cells. Based on their mechanism of action, these systems are classified into one-step and two-step pathways.One-Step Secretion Systems (Types I, III, IV, and VI)One-step secretion systems bypass the periplasm entirely, forming a continuous channel that spans both the inner and outer membranes:Type I Secretion System (T1SS):...
49
Vesicular Tubular Clusters
2.5K
After budding out from the ER membrane, some COPII vesicles lose their coat and fuse with one another to form larger vesicles and interconnected tubules called vesicular tubular clusters or VTCs. These clusters constitute a compartment at the ER-Golgi interface known as ERGIC (Endoplasmic Reticulum Golgi Intermediate Compartment). The ERGIC is a mobile membrane-bound cargo transport system that sorts proteins secreted from ER and delivers them to the Golgi.
With the help of motor proteins such...
With the help of motor proteins such...
2.5K
Coat Assembly and GTPases
3.6K
Vesicles incorporate different coat protein subunits in different cell locations, which changes the properties of the coat, such as the shape and geometry of the transport vesicles. Thus, vesicle coat proteins also play a significant role in cargo selection.
Coat assembly depends on the local availability of phosphatidylinositol phosphates or PIPs and GTP-binding proteins. Adaptor proteins, which link the coat proteins to the membrane, bind to these PIPs and play a crucial role in controlling...
Coat assembly depends on the local availability of phosphatidylinositol phosphates or PIPs and GTP-binding proteins. Adaptor proteins, which link the coat proteins to the membrane, bind to these PIPs and play a crucial role in controlling...
3.6K
Bacterial Translocation and Protein Secretion
39
Bacterial protein secretion involves translocation systems to ensure proteins reach their designated locations, including the plasma membrane, periplasm, outer membrane, or the external environment. These translocation systems are vital for bacterial physiology, supporting processes like membrane assembly, enzymatic activity in the periplasm, and interactions with the external environment. The division of labor between Sec and Tat pathways ensures efficiency in handling proteins with diverse...
39
COP Coated Vesicles
7.9K
Membrane-enclosed structures called vesicles transport proteins and lipids across the cell. The vesicles derive their cargo from the plasma membrane, Golgi, ER, or endosome. Coated vesicles are spherical, protein-coated carriers with a 50–100 nm diameter that mediate bidirectional transport between the ER and the Golgi. The distribution of proteins between the ER and Golgi complex is dynamic and is maintained by different coated vesicles. Their formation is driven by the assembly of...
7.9K


