Coil conversion to β-strand induced by dimerization

Area of Science:

• Molecular Biology
• Structural Biology
• Biochemistry

Background:

• Protein-protein interactions are crucial for molecular processes in living organisms.
• Many protein interactions are mediated by beta-sheet interfaces.
• Understanding the formation and stability of these interfaces is key to deciphering protein function.

Purpose of the Study:

• To investigate the conversion of protein coils into beta-strands for forming beta-sheet interfaces.
• To characterize and analyze these 'dimorphic' beta-strand interfaces.
• To develop a method for predicting sequences that form dimorphic beta-strand interfaces.

Main Methods:

• Conducted an exhaustive search of the Protein Data Bank to identify relevant structural fragments.
• Extracted, characterized, and analyzed dimorphic coil-to-beta-strand fragments.
• Developed a computational classifier to distinguish between dimorphic and standard beta-strand interface sequences.

Main Results:

• Identified dimorphic fragments with short strand lengths and specific amino acid profiles.
• Found that dimorphic beta-strand interfaces are likely less stable than standard interfaces.
• Demonstrated that these interfaces can potentially convert to coil interfaces under altered environmental conditions.
• Successfully constructed a classifier capable of predicting dimorphic sequences.

Conclusions:

• Dimorphic beta-strand interfaces represent a distinct class of protein interaction sites.
• Their inherent instability suggests a dynamic role in protein complex formation.
• The developed classifier offers a novel approach for identifying proteins with the potential to form dimers.