Bacterial ClpP Protease Is a Potential Target for Methyl Gallate

Area of Science:

• Microbiology
• Bacteriology
• Molecular Biology

Background:

• Methyl gallate (MG) shows microbicidal activity with potential in plant disease management and clinical settings.
• The specific molecular target of methyl gallate in bacteria remains unidentified.

Purpose of the Study:

• To identify the molecular target of methyl gallate (MG) in the plant pathogenic bacterium *Ralstonia solanacearum*.
• To elucidate the mechanism of action of methyl gallate.

Main Methods:

• Transposon sequencing (Tn-seq) was employed to screen for genes conferring resistance to MG.
• Gene deletion, iTRAQ proteomics, and molecular docking were used for validation and mechanistic studies.

Main Results:

• Mutation in the caseinolytic protease proteolytic subunit gene (*clpP*) significantly increased *R. solanacearum* resistance to MG.
• ClpP degrades chemotaxis, flagella, and sulfur metabolism-associated proteins; MG treatment upregulated these proteins in wild-type but not *clpP* mutants.
• Molecular docking suggested a direct interaction between MG and ClpP.

Conclusions:

• Methyl gallate (MG) likely targets bacterial ClpP, inhibiting its activity and disrupting bacterial proteostasis.
• This study provides a theoretical foundation for utilizing MG in controlling plant diseases and for potential therapeutic applications.