Creating novel proteins by combining design and selection

We present the results of combining design and selection to remodel a protein-peptide binding interface, using the peptide PTIEEVD and the TPR1 module interaction as our test case. We initially used the program Rosetta to interrogate possible TPR1 sequences compatible with binding the peptide PTIEEVD. Based on these results, we screened a small library of TPR1 variants, using a split GFP fluorescent assay to identify proteins that are able to bind to the PTIEEVD peptide. We discuss the similarities and differences between the modeling and selection results at each position. We show that a new 'consensus' TPR1, created based on the results of the sequences identified in the screen, indeed binds to the PTIEEVD peptide. These results demonstrate the utility of combining design and selection in a synergistic fashion to remodel protein recognition interfaces.