An efficient labeling method to map protein-protein interactions

The goals of this study is to identify interface residues in protein complexes using cysteine scanning mutagenesis coupled to yeast surface display and deep sequencing. This method involves screening a panel of purified cognate proteins against a panel of chemically masked single cysteine mutants of its interacting partner. The binding residues are deciphered by probing the loss of binding to the labeled cognate partner.