| The backbone fold of the Src SH2 domain is shown in green. The domain has a central β-sheet that divides the phosphotyrosine-binding pocket, to the right, from the specificity pocket on the left. A phosphopeptide ligand, with the sequence pYEEI is shown in gold, with the sidechains of the amino acids depicted. The phosphate moiety of the phosphotyrosine residue is shown in red, and the critical arginine in the SH2 phosphotyrosine binding pocket is in blue. The peptide traverses the central β-sheet, so that the more C-terminal peptide residues interact with the specificity pocket of the SH2 domain. In particular the isoleucine at the +3 position fits into a hydrophobic pocket in the SH2 domain. (PDB 1sps) |
