T4菌体病毒的进化是由非细菌因素的选择压力驱动的
Joanna Majewska1, Paulina Miernikiewicz1, Aleksander Szymczak1
1Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences , Wrocław, Poland.
Microbiology spectrum
|September 19, 2023
概括
菌体T4头蛋白gp24和Soc提高了胃肠道中的存活率. 由于缺乏这些蛋白质,T4菌体对pH值,酶和温度的稳定性降低,影响其持久性.
科学领域:
- 微生物学 微生物学
- 病毒学 病毒学
- 分子生物学分子生物学
背景情况:
- 菌体是感染细菌的病毒,在动物和人类的胃肠道 (GI) 中大量存在.
- 类似T4的菌体,如Bacteriophage T4,依赖于像大肠杆菌这样的共生体.
- 菌体T4的复杂结构,特别是它的囊体,对于菌体在各种环境中的适应性至关重要.
研究的目的:
- 为了研究单个菌体T4头蛋白 (gp24,Hoc和Soc) 在非细菌性压力下菌体生存中的作用.
- 评估这些蛋白质对T4菌体稳定性的影响,在适用于肠道的条件下,包括pH值,温度和消化酶.
主要方法:
- 在头蛋白 gp24,Hoc 和 Soc 的基因中构建 T4 菌体变异与删除或旁路.
- 测试这些变体对低pH值,高温和消化酶的敏感性.
- 在37°C的温度下评估菌体活动,在特定头部蛋白质的存在和缺乏的情况下.
主要成果:
- 简化体结构的菌体变体 (∆24byp24) 在低pH下表现出较低的稳定性和对消化酶的敏感性增加.
- 缺少gp24和Soc蛋白质导致T4菌体活动在37°C显著下降.
- Gp24表现出高耐热和化学变性,而Soc则充当稳定"分子"的作用.
结论:
- 在T4进化的后期获得的gp24蛋白质对于在肠道中承受环境挑战至关重要.
- 该Soc蛋白增强gp24的保护作用,有助于整体菌体的稳定性.
- 菌体囊体结构,特别是像gp24和Soc这样的蛋白质,在宿主肠道环境中的T4菌体持久性中起着至关重要的作用.
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