Structural insight, mutation and interactions in human Beta-catenin and SOX17 protein: A molecular-level outlook for...

Area of Science:

• Structural biology
• Computational biophysics
• Developmental biology

Background:

• SOX17-HMG domain and beta-catenin are essential human proteins critical for vertebrate gastrulation and embryonic development.
• Previous experimental studies confirmed their interaction, noting altered binding upon specific mutations (M76A, G103R).

Purpose of the Study:

• To perform the first computational analysis of SOX17-HMG domain and beta-catenin interactions, focusing on the impact of mutations.
• To elucidate the molecular mechanisms underlying altered protein-protein interactions due to SOX17-HMG mutations.

Main Methods:

• Extraction and analysis of experimentally validated 3D models of SOX17-HMG domain and beta-catenin.
• Computational modeling, energy minimization, and molecular dynamics simulations of wild-type and mutant SOX17-HMG complexed with beta-catenin.
• Analysis of evolutionary conservation, sequence alterations, and interaction types (ionic, stability).

Main Results:

• A significant reduction in ionic interactions was observed between mutant SOX17-HMG and beta-catenin (5 vs. 16 in wild-type).
• Glutamate (Glu) residues in wild-type SOX17-HMG were crucial, contributing to 50% of ionic interactions.
• Molecular dynamics simulations indicated reduced stability and a helix-to-coil transition in the mutant SOX17-HMG, suggesting a weaker conformation.

Conclusions:

• Mutations in SOX17-HMG significantly destabilize its interaction with beta-catenin, primarily by reducing ionic interactions.
• The findings provide a detailed molecular understanding of how SOX17-HMG mutations can impair protein interactions and potentially hinder signal transduction.
• This research offers insights for future pharmaceutical development targeting these essential human proteins.