Internal symmetry in protein structures: prevalence, functional relevance and evolution

Area of Science:

• Structural biology
• Bioinformatics
• Evolutionary biology

Background:

• Symmetry is observed across biological organization levels, particularly in protein structures.
• Evolutionary studies suggest links between internal protein symmetry, quaternary structure, and function.
• Computational tools like SymD and CE-Symm enable large-scale symmetry detection.

Purpose of the Study:

• To investigate the prevalence and implications of internal symmetry in protein structures.
• To explore the relationship between protein symmetry, structural integrity, and biological function.

Main Methods:

• Utilized computational methods (SymD, CE-Symm) for large-scale detection of internal symmetry in protein structures.
• Analyzed data from the Structural Classification of Proteins (SCOP) database.

Main Results:

• Approximately 20% of SCOP folds, superfamilies, and families show internal symmetry.
• All-beta and membrane protein classes exhibit a higher frequency of internal symmetry.
• Regions connecting symmetric units may correlate with functionally important sites.

Conclusions:

• Internal symmetry is a significant feature in a substantial portion of protein structures.
• Further research is needed to establish general principles governing protein internal symmetry and its functional relevance.