Bacterial Signalling: Two-component Systems

This lecture covers the two-component signalling systems in bacteria, where signal transduction is achieved by phosphorylation of a response regulator by a histidine kinase. The histidine kinases are typically transmembrane homodimeric proteins with an ATP-binding domain. Response regulators, often multi-domain proteins, play a crucial role in gene expression regulation. The lecture also discusses the phosphorylation and dephosphorylation processes involved in signal transduction, as well as the correlation between swimming behavior and flagellar rotation in E. coli, highlighting the importance of chemotaxis in bacterial movement and food source localization. Additionally, the mechanisms of receptor desensitization through methylation and the interplay between CheR and CheB in optimizing chemotaxis are explained.