在囊降解菌体尾尖蛋白中映射结构约束和适应潜力
Sarah Evert1,2, Phill Huss1, Dinesh Kumar Kuppa Baskaran3,4
1Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA.
bioRxiv : the preprint server for biology
|November 24, 2025
概括
细菌体尾尖蛋白 (TSPs) 的深度突变扫描揭示了突变如何改变功能和宿主范围. 这项研究为工程菌体提供了一种策略,以对抗细菌囊防御.
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:
- 菌体尾尖蛋白 (TSPs) 对于在感染期间降解细菌囊至关重要.
- 了解TSP功能和宿主特异性的分子基础对于菌体治疗的发展至关重要.
- 细菌菌体的宿主范围通常受到细菌囊结构的限制.
研究的目的:
- 研究来自大肠杆菌K1菌K1F的特定菌体尾尖蛋白 (TSP) 的功能和适应性场景.
- 确定确定TSP酶活性,过程性和宿主特异性的关键残留物和结构元素.
- 为设计能够克服囊介导细菌耐药性的菌体提供见解.
主要方法:
- 深度突变扫描 (DMS) 用于 *Escherichia coli* K1菌体 K1F. 的内聚酶 TSP.
- 使用一个改进的Oracle菌体工程平台,产生了超过22,000个单氨基酸变体.
- 通过比较选择,在工程 TSP 变体中评估了功能活动,过程性和宿主特异性.
主要成果:
- 发现TSP结构脆弱,但具有适应性灵活性,特定突变影响功能.
- 活性部位的突变适应了较长的酸链,扩大了基质识别.
- 该TSP茎作为一个"调旋"的过程性和特异性,而其他区域通过与囊修饰和O-抗原相互作用调节宿主范围.
结论:
- 菌体TSP中的特定突变可以显著调节它们的酶活性,基质特异性和宿主范围.
- 该研究阐明了TSP的结构功能关系,突出了茎和远端区域作为宿主相互作用的关键调节器.
- 这些发现为合理设计菌体提供了一个框架,以克服细菌囊防御并提高治疗效果.
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