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通过脂蛋白NlpI招募丁糖甘氨酸内酶MepS的结构基础

Shen Wang¹, Chun-Hsiang Huang², Te-Sheng Lin¹

¹Institute of Biochemistry and Molecular Biology, College of Medicine, National Taiwan University, Taipei, Taiwan.

Nature communications

|June 27, 2024

概括

适配器NlpI通过招募多个内酶MepS分子来增强酸甘 (PG) 水解,促进MepS活动. 此外,NlpI还促进了 MepS 通过蛋白酶 Prc 降解,调节了 PG 扩张.

科学领域:

细菌细胞壁生物学细菌细胞壁生物学
结构生物学是结构生物学.
酶学是一种酶学.

背景情况:

糖 (PG) 囊保持细菌细胞的完整性,抵御压.
PG内酶对于细胞生长至关重要,使新的甘氨酸结合和网状扩张成为可能.
外膜蛋白NlpI将水解酶和合成酶定位到PG合成部位,用于局部水解.

研究的目的:

阐明NlpI影响糖甘 (PG) 内酶活性和调节的结构机制.
确定NlpI-MepS相互作用的原子细节及其对MepS功能的影响.
研究NlpI在MepS被蛋白酶Prc.降解中的作用.

主要方法:

使用X射线晶体学来确定NlpI与MepS复合的结构,以及与Prc-MepS复合的结构.
生物化学测试被用来评估MepS活性和降解率.
进行了对内在无序区域和蛋白质与蛋白质相互作用的分析.

主要成果:

NlpI结合会在MepS的N端引发一个从异常到异常的过渡,促进MepS的二元化,并增强其PG水解活性.
NlpI充当支架,对齐两个MepS二元体以最大限度地提高酶效率.
Prc-NlpI-MepS复杂结构揭示了NlpI调解了MepS和Prc之间的相互作用,导致有效的MepS降解.

结论:

NlpI利用一种激发效应来促进细胞内酶活性.
在规范MepS方面,NlpI扮演着双重的角色:增强其活动,并促进其通过Prc.降解.
这些发现提供了对细菌生长过程中甘重塑调节的关键结构见解.

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