A Designed Zn²⁺ Sensor Domain Transmits Binding Information to Transmembrane Histidine Kinases.

Area of Science:

• Protein Engineering
• Biochemistry
• Molecular Biology

Background:

• Bacterial histidine kinases (HKs) are crucial for signal transduction, involving ligand binding, signal amplification across membranes, and phosphorylation relays.
• Engineering stimulus-responsive allosteric signaling de novo remains a significant challenge in protein design.

Purpose of the Study:

• To investigate if current protein design principles allow engineering of a histidine kinase (HK) with tunable de novo components.
• To explore the feasibility of creating novel, stimulus-responsive transmembrane signaling systems.

Main Methods:

• Generated de novo metal-binding sensor domains.
• Substituted these designed sensor domains into a native transmembrane HK.
• Created chimeric HKs to test de novo signal transduction.

Main Results:

• Successfully generated chimeric HKs that transduce signals initiated by de novo sensor domains.
• Demonstrated that signaling efficacy is dependent on the designed sensor's stability.
• Showed that interdomain linker characteristics (phase and length) critically influence signal transduction.

Conclusions:

• De novo design is a powerful approach to elucidate biochemical mechanisms of transmembrane signaling.
• The study highlights the successful engineering of functional, stimulus-responsive signaling systems using designed protein components.
• Results provide insights into the principles governing intramolecular signaling and protein design.