Most yeast SH3 domains bind peptide targets with high intrinsic specificity

Area of Science:

• Computational Biology and Bioinformatics
• Molecular Evolution and Genomics
• Protein Science and Structural Biology

Background:

• Predicting protein function differences is crucial, especially for protein domain families with conserved folds but diverse functions.
• Evolutionary conservation of protein domains provides genomic data for analyzing functional divergence.
• Identifying specific binding residues is key to understanding protein-target interactions.

Purpose of the Study:

• To develop a bioinformatics method for predicting unique peptide-binding specificities within protein domain families.
• To test the hypothesis that sequence alignment analysis across ancestral species can reveal specific binding residues.
• To apply this method to the yeast SH3 domain family to understand its peptide-binding diversity.

Main Methods:

• Grouped domain sequences to identify common and unique binding residues.
• Performed sequence alignment analysis of the yeast SH3 domain family across ancestral fungal species.
• Defined specific residues as those poorly conserved in paralogs but conserved in orthologs.

Main Results:

• Identified unique amino acid conservation patterns in most yeast SH3 domain family members.
• These patterns suggest high intrinsic specificity for peptide targets via non-canonical recognition.
• A minority of domains showed less diverse binding surfaces, potentially requiring additional factors for specific binding.

Conclusions:

• The developed bioinformatics approach successfully predicts intrinsic binding specificity within the yeast SH3 domain family.
• Predictions align with high-throughput binding data, validating the method's efficacy.
• This approach is applicable to other evolutionarily conserved interaction domain families for predicting binding specificity.