Structural and functional analysis of multiprotein complexes required for colicin translocation

大肠菌素易位所需的多蛋白复合物的结构和功能分析

• 批准号: BB/D016320/1
• 负责人: Richard James
• 金额: $ 46.11万
• 依托单位: University of Nottingham
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2006
• 资助国家: 英国
• 起止时间: 2006 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FD016320%2F1
• 关键词: Structural; functional; analysis; multiprotein; complexes

Bacterial cells can export many proteins from the cytoplasm to the outside of the cell, including toxins that are capable of causing damage to humans that come into contact with them. The mechanisms of protein export have been well characterised in the last 20 years. In contrast the import of proteins into bacterial cells from the outside is a rare event that is limited to colicins; protein antibiotics produced by bacteria to kill closely related species in order to gain a selective advantage. An example is colicin E9 which has a C-terminal cytotoxic domain that has deoxyribonuclease (DNase) activity. If delivered into E.coli cells the DNase attacks and degrades their DNA in the cytoplasm and leads to cell death. The process by which the cytotoxic DNase domain is delivered from outside the cell into the cytoplasm is called translocation, and involves the interaction of the N-terminal translocation domain of colicin E9 with a number of E.coli proteins. The molecular details of how the protein-protein interactions involving the translocation domain result in the delivery of the DNase domain into the cytoplasm are poorly understood. This project aims to generate data so that better models of the translocation process can be formulated. Our proposed studies have potential implications in the development of new antibiotics and improving our understanding of the process by which complexes of proteins are formed.

细菌细胞可以将许多蛋白质从细胞质输出到细胞外，包括能够对接触它们的人造成伤害的毒素。蛋白质输出的机制在过去20年中得到了很好的表征。相比之下，从外部将蛋白质输入细菌细胞是一种罕见的事件，仅限于大肠杆菌素;细菌产生的蛋白质抗生素杀死密切相关的物种，以获得选择性优势。一个实例是大肠杆菌素E9，其具有具有脱氧核糖核酸酶（DNA酶）活性的C-末端细胞毒性结构域。如果被递送到大肠杆菌细胞中，DNA酶会攻击并降解细胞质中的DNA并导致细胞死亡。将细胞毒性DNA酶结构域从细胞外递送到细胞质中的过程称为易位，并且涉及大肠杆菌素E9的N-末端易位结构域与许多大肠杆菌蛋白质的相互作用。涉及易位结构域的蛋白质-蛋白质相互作用如何导致DNA酶结构域递送到细胞质中的分子细节知之甚少。该项目旨在生成数据，以便制定更好的易位过程模型。我们提出的研究对开发新抗生素和提高我们对蛋白质复合物形成过程的理解具有潜在意义。

项目成果

The crystal structure of the TolB box of colicin A in complex with TolB reveals important differences in the recruitment of the common TolB translocation portal used by group A colicins.

• DOI: 10.1111/j.1365-2958.2009.06808.x
• 发表时间: 2010-02
• 期刊: Molecular microbiology
• 影响因子: 3.6
• 作者: Zhang Y;Li C;Vankemmelbeke MN;Bardelang P;Paoli M;Penfold CN;James R
• 通讯作者: James R