Uncovering the Interaction Interface Between Harpin (Hpa1) and Rice Aquaporin (OsPIP1;3) Through Protein-Protein...

Area of Science:

• Plant pathology
• Molecular biology
• Biophysics

Background:

• Harpin protein Hpa1 from Xanthomonas Oryzae pv. oryzae (Xoo) is crucial for Type III Secretion System assembly during plant infection.
• Harpins can induce plant defense responses like hypersensitive response and systemic acquired resistance.
• Understanding plant-harpin interactions is vital for agricultural applications, but the structural basis remains unclear.

Purpose of the Study:

• To elucidate the structural basis of the interaction between Hpa1 and rice aquaporin OsPIP1;3.
• To investigate the stability and key interacting residues of the Hpa1-OsPIP1;3 complex using computational methods.

Main Methods:

• In silico protein-protein interaction (PPI) analysis.
• Molecular dynamics (MD) simulations to assess complex stability.
• Analysis of Root Mean Square Deviation (RMSD) and residue-wise fluctuations.

Main Results:

• The N-terminal amino acids of Hpa1 were identified at the interface of the Hpa1-OsPIP1;3 complex.
• MD simulations demonstrated the stability of the complex, with specific RMSD values for OsPIP1;3, Hpa1, and the complex.
• Residue-wise fluctuations were analyzed post-MD simulations.

Conclusions:

• This study provides the first in silico insights into the structural basis of harpin protein-aquaporin interaction.
• The findings lay a foundation for understanding interactions with other harpin protein orthologs.
• This work opens new avenues for structural-functional relationship studies of harpin proteins and their agricultural potential.