Fig. 3.
Peptide library layout in stock plate and for kinase in the upper quadrant of reaction plate. The peptide sets with fixed residues N-terminal to the phosphosite (labeled −5 through −1) are on the left side of the plate (columns 2–23), and the peptide sets with fixed residues C-terminal to the phosphosite (labeled +1 through +4) are on the right side of the plate (columns 26–47). Letters indicate the fixed amino acid, where pT is phosphothreonine, pY is phosphotyrosine.