Truncated, Non-networking Versions of the Coupling Protein CheW Retain Chemoreceptor Control of Kinase CheA

J Mol Biol. 2020 Jan 17;432(2):576-584. doi: 10.1016/j.jmb.2019.09.009. Epub 2019 Oct 16.

Abstract

Bacterial chemoreceptors control the activity of the associated CheA kinase in response to chemical gradients and, consequently, regulate the swimming behavior of the cell. However, such control is not direct but requires the participation of the essential coupling protein CheW, which is structurally homologous to the carboxy-terminal domain of the kinase. The actual role of this small coupling protein is somehow intriguing. It has been demonstrated that it is absolutely essential for chemoreceptor control of the kinase, in spite of the occurrence of direct contacts between chemoreceptors and CheA. In addition, CheW plays an essential role in the assembly of the large macromolecular arrays that combine chemoreceptors of different specificities, and it is therefore responsible for molecular interactions that provide such arrays with remarkable signaling properties. In this work, we analyze truncated CheW derivatives that are still able to control the kinase but have lost the ability to connect signaling units. We demonstrate that these two activities can work separately and speculate about the significance of the roles of these two different activities in the context of the chemoreceptor cluster.

Keywords: CheW coupling protein; Chemoreceptor complex; Networking CheW activity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / genetics
  • Bacterial Proteins / ultrastructure*
  • Binding Sites
  • Chemotaxis* / genetics
  • Escherichia coli / genetics
  • Escherichia coli / ultrastructure*
  • Escherichia coli Proteins / genetics
  • Escherichia coli Proteins / ultrastructure*
  • Histidine Kinase / genetics
  • Histidine Kinase / ultrastructure*
  • Methyl-Accepting Chemotaxis Proteins / genetics
  • Methyl-Accepting Chemotaxis Proteins / ultrastructure*
  • Models, Molecular
  • Protein Binding
  • Protein Conformation
  • Signal Transduction / genetics
  • Structural Homology, Protein

Substances

  • Bacterial Proteins
  • Escherichia coli Proteins
  • Methyl-Accepting Chemotaxis Proteins
  • CheW protein, Bacteria
  • Histidine Kinase
  • cheA protein, E coli