Identification of a distal allosteric ligand binding pocket in HtrA3

Area of Science:

• Biochemistry
• Molecular Biology
• Enzymology

Background:

• Human High temperature requirement protease A3 (HtrA3) is a serine protease implicated in cancer and pre-eclampsia.
• HtrA3 is proposed as a tumor suppressor, highlighting its therapeutic potential.
• Allosteric regulation is a known mechanism for HtrA3 homolog activation, suggesting potential for enzyme manipulation.

Purpose of the Study:

• To investigate the allosteric behavior of human HtrA3.
• To identify novel binding sites and understand their role in HtrA3 regulation.
• To elucidate the mechanism of catalytic activation and substrate binding for HtrA3.

Main Methods:

• In silico computational approaches including molecular docking and simulation studies.
• Biochemical assays to validate computational findings.
• Analysis of conformational changes and signal propagation within HtrA3.

Main Results:

• First-time demonstration of allosteric behavior in human HtrA3.
• Identification of a novel, selective allosteric binding pocket.
• Characterization of conformational reorientations and signal propagation to the active site.
• Discovery of a non-classical binding site crucial for active site formation.

Conclusions:

• Human HtrA3 exhibits allosteric regulation through a novel binding site.
• This allosteric site influences the catalytic efficiency of the active site.
• Findings provide a basis for developing targeted therapeutic strategies for HtrA3-related diseases.