Correlated Evolution Drives Structural Convergence of Interacting Proteins

Understanding the relationship between protein structures and their interactions is a fundamental biological problem. Here we broadly tackle this problem by examining associations between protein structural features and interaction patterns in rodents and yeast-two highly divergent taxa from different kingdoms. In both taxa, we uncover positive correlations between intrinsic disorders of interacting proteins, consistent with a prior study showing stronger affinity between proteins with similar structures. However, closer examination reveals that these relationships are restricted to proteins involved in evolutionarily conserved interactions, or interologs. We also find that interologs generally exhibit more similar protein structures and less evolutionary structural divergence than non-interologs, supporting the hypothesis that conserved interactions are associated with structural convergence of interacting proteins. Further analyses show that interologs are typically less intrinsically disordered and play more central functional roles than non-interologs, suggesting that these structural similarities may help preserve stable interactions involved in essential biological processes. Overall, this study underscores the interconnected evolution of protein structures and their interactions, illustrating how the optimization of protein fitness landscapes for both structural and functional stability may promote structural convergence across divergent taxa.