葡萄球菌菌体异体化 φ2638A内素异型及其在细菌溶解中的功能作用
Léa V Zinsli1, Anna M Sobieraj1, Jiemin Du1
1Institute of Food Nutrition and Health, ETH, 8092 Zurich, Switzerland.
microLife
|June 30, 2025
概括
菌体内素具有短变异 (SV) 异型,可以在感染期间增强后代的释放. 这项研究揭示了SV异型.
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:
- 菌体内溶酶,向格拉姆阳性细菌,具有模块化结构,具有酶活性域 (EAD) 和细胞壁结合域 (CBD).
- 一些内素通过内部翻译起点 (iTSSs) 与全长 (FL) 版本一起产生短变异 (SV) 异形,但它们在菌体感染期间的作用尚不清楚.
研究的目的:
- 在葡萄球菌菌体 φ2638A 感染期间,研究全长 (FL) 内素,Ply2638A 和其短变体 (SV) 异型之间的功能相互作用.
- 阐明SV异形在菌体生命周期中的结构基础和功能意义.
主要方法:
- 通过X射线结晶学和AlphaFold建模,确定Ply2638A.的域函数.
- 在菌体感染期间证实了 SV 异型的产生,并分析了其与 FL endolysin 的复合形成.
- 菌体变异的基因工程,以评估单个和组合异形产生的对活动和后代释放的影响.
主要成果:
- 这些结构揭示了Ply2638A.内的M23内酶,氨基酶和SH3b域的独特功能.
- 这种SV异型 (胺基酶和SH3b域) 通过中间胺基酶域相互作用与FL Ply2638A形成异构体.
- 缺少FL或SV异型的菌体表现出后代释放的延迟和受损的Lytic活动,这可以通过补充部分恢复.
结论:
- 这种SV异型在增强细胞解离和后代菌体释放效率方面发挥着至关重要的作用,在解离周期结束时.
- 这项研究为菌体基因组中内部翻译起点 (iTSSs) 的进化保存提供了功能性解释.
- 虽然Ply2638A在培养中对金黄色葡萄球菌的活性不受SV异型补充的影响,但其在感染期间的作用至关重要.
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