In most signal transduction systems, coupling or scaffold proteins establish crucial connections between receptors and histidine kinases. These connections are important for signal transduction. The bacterial chemotaxis system is a canonical signal transduction system that relies on coupling proteins. The coupling proteins in the chemotaxis system have two architectures: CheW or CheV. In a typical chemotaxis signal transduction system, two CheW coupling protein molecules bridge a histidine kinase CheA dimer and two chemoreceptor (also called as methyl-accepting chemotaxis protein, MCP) trimers of dimers to form a core signaling complex and couple CheA activity to chemoreceptor control. Although CheW is a small cytoplasmic protein, it plays multiple functions in chemotaxis. CheW also builds connections between core signaling complexes, which leads to the formation of large chemosensory arrays that are responsible for collecting and amplifying signals from various chemoreceptors. Another coupling protein, CheV, shares a largely redundant ability with CheW; however, the function of CheV is not identical to that of CheW in chemotaxis. In this article, we summarize the molecular mechanism of chemotaxis in Escherichia coli and review the recent advances in the structural details and functions of CheW and CheV. Furthermore, we focus on the diversity of coupling proteins and discuss the relationship among multiple coupling proteins in one organism.

在大多数信号转导系统中，偶联蛋白或支架蛋白在受体和组氨酸激酶之间建立了至关重要的联系。这些连接对于信号转导很重要。细菌趋化性系统是依赖于偶联蛋白的规范信号转导系统。化学趋化系统中的偶联蛋白具有两种结构：CheW或CheV。在典型的趋化性信号转导系统中，两个CheW偶联蛋白分子桥接一个组氨酸激酶CheA二聚体和两个Checeptceptor（也称为甲基接受趋化蛋白，MCP）三聚体三聚体，形成核心信号复合物，并将CheA活性与化学感受器控制相偶联。 。尽管CheW是一种小的细胞质蛋白，但它在趋化性中起着多种功能。CheW还在核心信令复合体之间建立连接，这导致形成大型化学感应阵列，这些阵列负责收集和放大来自各种化学感受器的信号。另一种偶联蛋白CheV与CheW具有很大的冗余能力。但是，CheV的功能与CheW在趋化性上的功能并不相同。在本文中，我们总结了化学趋化作用的分子机制。大肠杆菌，并回顾CheW和CheV的结构细节和功能方面的最新进展。此外，我们专注于偶联蛋白的多样性，并讨论了一种生物中多种偶联蛋白之间的关系。