对细菌和密闭二元毒素的传递系统的结构和功能洞察
Spiridon E Sevdalis1,2,3, Kristen M Varney1,2,3, Mary E Cook1,3
1Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
Toxins
|August 28, 2024
概括
病原细菌如Bacillus和Clostridia使用二元毒素通过破坏宿主细胞来引起疾病. 本文重点介绍了这些毒素的结构,以及它们如何将酶输入细胞.
科学领域:
- 微生物学和分子生物学
- 细菌病原体的产生
- 结构生物学 结构生物学
背景情况:
- 病原性细菌和闭膜细菌产生各种效应蛋白,包括二进制毒素,以引起疾病.
- 二元毒素是AB型蛋白质复合体,会损害宿主上皮细胞,特别是在肠道.
- 毒性 (A) 子单元进入宿主细胞,ADP-ribosylates 活性蛋白,导致快速的细胞死亡.
研究的目的:
- 为了审查来自Bacillus thuringiensis,Clostridioides difficile和Clostridium perfringens的二元毒素.
- 专注于这些二元毒素的细胞结合和输送 (B) 子单元的结构阐明.
- 了解毒性酶向宿主细胞输送的机制.
主要方法:
- 对细菌二元毒素现有文献的审查.
- 对来自Bacillus thuringiensis,Clostridioides difficile和Clostridium perfringens的毒素B子单位的结构数据的分析.
- 整合结构发现与已知的毒素作用机制.
主要成果:
- 详细讨论了关键细菌病原体B子单元的结构特征.
- 了解B子单元如何促进与宿主细胞的结合和A子单元的转移.
- 毒素结构与actin的ADP-ribosylation过程之间的相关性.
结论:
- 对二元毒素B子单元的结构理解对于破译毒素输送机制至关重要.
- 这些毒素对人类,动物和昆虫的健康构成重大威胁.
- 对毒素结构功能关系的进一步研究可以为治疗策略提供信息.
相关概念视频
Receptor-mediated Endocytosis
6.0K
Receptor-mediated endocytosis is when bulk amounts of specific molecules are imported into a cell after binding to cell surface receptors. The molecules bound to these receptors are taken into the cell through inward folding of the cell surface membrane, which is eventually pinched off into a vesicle within the cell. Structural proteins, such as clathrin, coat the budding vesicle.
Clathrin-Mediated Endocytosis of LDL
One well-characterized example of receptor-mediated endocytosis is the...
Clathrin-Mediated Endocytosis of LDL
One well-characterized example of receptor-mediated endocytosis is the...
6.0K
Cytoskeletal Proteins in Bacteria
3.3K
Bacterial cells were initially considered simple, randomly organized structures lacking a cytoskeleton. However, the discovery of cytoskeleton homologs in bacteria led to the change of this opinion. Bacterial cytoskeletal filaments regulate the cell shape, cell polarity, cell division, and partitioning of plasmids during cell division. It was later discovered that bacterial cytoskeletal proteins, mainly actin and tubulin homologs, are diverse compared to their eukaryotic counterparts. On the...
3.3K
Fusion of Secretory Vesicles with the Plasma Membrane
11.0K
Proteins and neurotransmitters in secretory vesicles can be released from a cell upon vesicle docking, priming, and fusion with the plasma membrane. Vesicles are docked and primed in preparation for the quick exocytosis of their contents in response to a stimulus. The fusion process is mainly carried out by a SNAP Receptor or SNARE complex, consisting of synaptobrevin, syntaxin-1, and SNAP-25.
In 1993, Jim Rothman proposed that the antiparallel pairing of vesicular and transmembrane SNAREs, or...
In 1993, Jim Rothman proposed that the antiparallel pairing of vesicular and transmembrane SNAREs, or...
11.0K
Clathrin Coated Vesicles
6.9K
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...
6.9K
Viral Structure
61.9K
Viruses are extraordinarily diverse in shape and size, but they all have several structural features in common. All viruses have a core that contains a DNA- or RNA-based genome. The core is surrounded by a protective coat of proteins called the capsid. The capsid is composed of subunits called capsomeres. The capsid and genome-containing core are together known as the nucleocapsid.
61.9K
Intracellular Movement of Viruses and Bacteria
2.8K
Intracellular bacteria and viruses often comprise a group of highly infectious pathogens that can cause several diseases. Bacterial pathogens include those belonging to the genus Rickettsia responsible for conditions such as rocky mountain spotted fever and the Mediterranean spotted fever; Chlamydia, a genus responsible for a sexually transmitted disease; Coxiella burnetii, an agent responsible for Q fever. Viral pathogens include vaccinia—a poxvirus, and herpes simplex virus—a...
2.8K


