Structure-function analysis of Type IV secretion systems by cryo-electron microscopy

通过冷冻电子显微镜对 IV 型分泌系统进行结构功能分析

• 批准号: MR/K012401/1
• 负责人: Elena Orlova
• 金额: $ 84.64万
• 依托单位: Birkbeck, University of London
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2013
• 资助国家: 英国
• 起止时间: 2013 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=MR%2FK012401%2F1
• 关键词: Structure; function; analysis; Type; IV

Numerous diseases in humans, in other animals, and also in plants are caused by bacteria. The diseases are extremely diverse including food poisoning, tooth ache, anthrax, and even certain forms of cancer. Bacteria invented many various strategies to penetrate into different organisms to use their resources leading to illness of the host. These strategies, called bacterial pathogenicity, include transport of different important proteins and their complexes across the bacterial and cell membranes. To transfer toxic molecules and other proteins into target cells bacteria developed several types of special systems that are named as secretion systems. One of them that is characterised as a Type IV secretion (T4S) system is exceptionally adaptable to different conditions and able to transport large macromolecular complexes. For example, the human pathogen Helicobacter pylori, which plays a major role in the pathogenesis of peptic ulcers and gastric cancer, encodes a T4S system, the Cag-T4S system, which mediates the injection of the toxin CagA. T4S systems are macromolecular assemblies usually composed of 12 proteins (VirB1-11 and VirD4). Most T4S systems have three dedicated ATPases (VirD4 (or the coupling protein), VirB11, and VirB4) that play essential roles in supplying the energy for substrate translocation and apparatus assembly. Significant progress has been made in the past decade in our understanding of T4S systems: several structural elements were studied by crystallographic methods and the overall architecture of the T4S system core organisation was revealed by methods of electron microscopy. However, larger complexes remain to be investigated, notably a fully assembled T4S system containing all 12 components. Moreover, the dynamic nature of T4S systems remains to be revealed, including the exact role each ATPase plays during the secretion process. It has been shown that the ATPases VirD4, VirB11 and VirB4 interact with each other, and they are involved into substrate transfer process. However, very little is known concerning the details of the interactions of ATPases with each other and with the rest of the T4S apparatus. The overall aim of the project is to reveal the structural basis of interactions and signalling between ATPases and the central core. Combination of different methods such as molecular genetics, biochemistry, crystallography, and structural electron microscopy will reveal a total architecture of the T4S system and interactions between its components within this intricate system. Understanding how T4S system functions is a subject of this proposal and an important step for development of better treatment, and prevention of infectious diseases.

人类、其他动物和植物中的许多疾病都是由细菌引起的。这些疾病是非常多样化的，包括食物中毒，牙痛，炭疽，甚至某些形式的癌症。细菌发明了许多不同的策略来渗透到不同的生物体中，以利用它们的资源，导致宿主生病。这些策略称为细菌致病性，包括不同重要蛋白质及其复合物跨细菌和细胞膜的运输。为了将有毒分子和其他蛋白质转移到靶细胞中，细菌发展了几种类型的特殊系统，称为分泌系统。其中一种被称为IV型分泌（T4 S）系统，特别适用于不同的条件，并能够运输大分子复合物。例如，在消化性溃疡和胃癌的发病机制中起主要作用的人类病原体幽门螺杆菌编码T4 S系统，Cag-T4 S系统，其介导毒素CagA的注射。T4 S系统是由12种蛋白质（VirB 1 -11和VirD 4）组成的大分子组装体。大多数T4 S系统具有三种专用的ATP酶（VirD 4（或偶联蛋白）、VirB 11和VirB 4），它们在为底物移位和装置组装提供能量方面发挥重要作用。在过去的十年中，我们对T4 S系统的理解取得了重大进展：通过晶体学方法研究了几个结构元素，并通过电子显微镜方法揭示了T4 S系统核心组织的整体架构。然而，更大的复合体仍有待研究，特别是包含所有12个组件的完全组装的T4 S系统。此外，T4 S系统的动态性质仍有待揭示，包括每个ATP酶在分泌过程中发挥的确切作用。研究表明，三种ATP酶VirD 4、VirB 11和VirB 4相互作用，参与底物转移过程。然而，很少有人知道有关的相互作用的ATP酶与彼此和与T4 S装置的其余部分的细节。该项目的总体目标是揭示ATP酶和中央核心之间相互作用和信号传导的结构基础。结合不同的方法，如分子遗传学，生物化学，晶体学和结构电子显微镜将揭示T4 S系统的总架构及其组成部分之间的相互作用在这个复杂的系统。了解T4 S系统如何发挥作用是本提案的主题，也是开发更好的治疗和预防传染病的重要一步。

项目成果

The ribosome and its role in protein folding: looking through a magnifying glass.

• DOI: 10.1107/s2059798317007446
• 发表时间: 2017-06-01
• 期刊: Acta crystallographica. Section D, Structural biology
• 作者: Javed A;Christodoulou J;Cabrita LD;Orlova EV
• 通讯作者: Orlova EV

Use of chimeric type IV secretion systems to define contributions of outer membrane subassemblies for contact-dependent translocation.

• DOI: 10.1111/mmi.13700
• 发表时间: 2017-07
• 期刊: Molecular microbiology
• 影响因子: 3.6
• 作者: Gordon JE;Costa TRD;Patel RS;Gonzalez-Rivera C;Sarkar MK;Orlova EV;Waksman G;Christie PJ
• 通讯作者: Christie PJ

Bacterial Secretion Systems - Methods and Protocols

细菌分泌系统 - 方法和方案

• DOI: 10.1007/978-1-0716-3445-5_27
• 发表时间: 2024
• 作者: Ignatiou A

Structure of a type IV secretion system.

• DOI: 10.1038/nature13081
• 发表时间: 2014-04-24
• 期刊: Nature
• 影响因子: 64.8

Structure of a VirD4 coupling protein bound to a VirB type IV secretion machinery.

• DOI: 10.15252/embj.201796629
• 发表时间: 2017-10-16
• 期刊: The EMBO journal
• 作者: Redzej A;Ukleja M;Connery S;Trokter M;Felisberto-Rodrigues C;Cryar A;Thalassinos K;Hayward RD;Orlova EV;Waksman G
• 通讯作者: Waksman G