打破障碍:pCF10类型4分泌系统依赖于自我调节的muramidase来调节细胞壁的分泌
Wei-Sheng Sun1,2, Gabriel Torrens3, Josy Ter Beek1,2
1Department of Medical Biochemistry and Biophysics, Umeå University, Umeå, Sweden.
mBio
|June 28, 2024
概括
结合性4型分泌系统 (T4SSs) 传播抗生素耐药性. 研究人员发现了PrgK酶.
科学领域:
- 微生物学 微生物学
- 分子生物学分子生物学
- 生物化学 生物化学
背景情况:
- 结合性4型分泌系统 (T4SSs) 对细菌中抗生素耐药性和毒性因子的传播至关重要.
- 了解阳性T4SSs至关重要,因为它们与许多医院获得的感染有关.
研究的目的:
- 阐明PrgK的功能和调节,PrgK是Gram阳性肠球菌结合性等离子体pCF10 T4SS中的一个关键细胞壁酶.
- 描述PrgK的三个预测的细胞外酸酶域的酶活性:LytM,可溶性酸转糖酶 (SLT) 和CHAP.
主要方法:
- 对LytM域的结构分析.
- 在体外酶测试以确定SLT域的活性.
- 调查LytM和CHAP领域对SLT活动的监管作用.
- 评估CHAP域在PrgK二元化中的作用.
- 确定PrgK与其他T4SS组件之间的相互作用,例如PrgL.
主要成果:
- LytM域的活性位点已经退化,缺乏必要的金属辅因子.
- SLT域表现出意想不到的muramidase活性,而不是液性转糖酶活性.
- LytM和CHAP域降低了SLT木胺酶活动的调节.
- CHAP域对于PrgK二聚体的形成至关重要.
- PrgK 与 PrgL 相互作用,可能有助于它在 T4SS.
结论:
- PrgK的功能域及其调节相互作用对格兰阳性T4SS功能至关重要.
- SLT域的意想不到的muramidase活性和LytM和CHAP的调节作用为结合过程中细胞外水解提供了新的见解.
- 这项研究增强了对*Enterococcus faecalis*和其他医学上相关的格拉姆阳性细菌水平基因转移机制的理解.
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