C-type lectin-(like) fold - Protein-protein interaction patterns and utilization

Area of Science:

• Structural biology
• Immunology
• Biotechnology

Background:

• The C-type lectin-like (CTL) fold is a conserved protein domain found in various proteins, including those involved in innate immunity, antimicrobial defense, and diseases like allergies and autoimmunity.
• CTL domains possess a characteristic structure with alpha-helices, beta-sheets, and disulfide bridges, enabling interactions with target molecules through diverse surface regions.

Purpose of the Study:

• To analyze the interaction patterns of the CTL fold using available structural data.
• To understand the rules governing CTL protein interactions for predicting function and designing novel protein binders.

Main Methods:

• Analysis of over 500 three-dimensional structures of CTL fold-containing proteins and their complexes from the Protein Data Bank.
• Sequence/structure/interaction correlation analysis to decipher interaction rules.

Main Results:

• The CTL fold utilizes almost its entire surface for protein:protein interactions, with a canonical interaction region being most frequent.
• Different interaction categories exhibit distinct interface strategies; strong binders feature large interaction areas, hydrophobic cores, or high surface complementarity.
• Interaction surfaces are not conserved in amino acid sequence, offering flexibility for binder design.

Conclusions:

• Structural data provides a comprehensive view of CTL fold interaction patterns, valuable for understanding uncharacterized CTL proteins.
• Insights gained can guide the development of new protein binders based on the CTL fold for biomedical and biotechnological applications.