Identification of ligands for bacterial sensor proteins

Curr Genet. 2016 Feb;62(1):143-7. doi: 10.1007/s00294-015-0528-4. Epub 2015 Oct 28.


Bacteria have evolved a variety of different signal transduction mechanisms. However, the cognate signal molecule for the very large amount of corresponding sensor proteins is unknown and their functional annotation represents a major bottleneck in the field of signal transduction. The knowledge of the signal molecule is an essential prerequisite to understand the signalling mechanisms. Recently, the identification of signal molecules by the high-throughput protein screening of commercially available ligand collections using differential scanning fluorimetry has shown promise to resolve this bottleneck. Based on the analysis of a significant number of different ligand binding domains (LBDs) in our laboratory, we identified two issues that need to be taken into account in the experimental design. Since a number of LBDs require the dimeric state for ligand recognition, it has to be assured that the protein analysed is indeed in the dimeric form. A number of other examples demonstrate that purified LBDs can contain bound ligand which prevents further binding. In such cases, the apo-form can be generated by denaturation and subsequent refolding. We are convinced that this approach will accelerate the functional annotation of sensor proteins which will help to understand regulatory circuits in bacteria.

Keywords: Bacterial virulence; Chemoreceptor; Ligand binding domain; Sensor protein; Signal transduction; Thermal shift assay.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Bacterial Physiological Phenomena*
  • Bacterial Proteins / chemistry
  • Bacterial Proteins / metabolism*
  • Ligands*
  • Protein Binding
  • Protein Interaction Domains and Motifs
  • Protein Multimerization
  • Recombinant Proteins
  • Signal Transduction*


  • Bacterial Proteins
  • Ligands
  • Recombinant Proteins