calorimetric examination of high-affinity Src SH2 domain-tyrosyl phosphopeptide binding: dissection of the phosphopeptide sequence specificity and coupling energetics

A study on Src homology 2 (SH2) domains and their functions investigated the specificity of the phosphopeptide interaction involving the Src SH2 domain and a peptide containing the sequence PQpYEEIPI (pYEEI). The study also probed the energetic coupling between the +1 Glu, +2 Glu and +3 Ile phosphopeptide residues. Among other results, it was found that the Src SH2 domain is quite permissive of conservative substitutions in the EEI motif at all three peptide positions.