Signal Transduction in Two-Component Systems: Kinase and Regulator Domains #2173125 (License: Personal Use)

The diagram depicts a canonical bacterial two-component signal transduction system. An external signal binds the input domain of a sensor histidine kinase, triggering ATP-dependent autophosphorylation at a conserved histidine (H) residue in its kinase domain; the phosphate is then transferred to an aspartate (D) in the receiver domain of a response regulator, activating its output domain (e.g., DNA-binding). Key domains labeled include N, G1, F, G2 in the kinase and DD, D1, K in the receiver, reflecting conserved motifs critical for function.

Used in microbiology and molecular biology educational content, research overviews, or textbook figures to explain how prokaryotes sense and respond to environmental changes; matches user intent for learning mechanisms of bacterial adaptation, quorum sensing, or antibiotic resistance pathways.