Figure 1

The Fyn tyrosine kinase and its SH2 domain. The Fyn tyrosine kinase (A) consists of three domains: the N-terminal domain SH3, an SH2 domain that binds phosphotyrosine motifs, the SH1 domain with tyrosine kinase activity and a short C-terminal tail. When inactive, the tyrosine at position 527 in the C-terminal part is phosphorylated and bound to the SH2 domain. In (B) the SH2 domain together with the bound C-terminal phosphotyrosine peptide is visualized. The standard nomenclature for the secondary structure elements is added, see also (D). (C) Close-up view of the phosphopeptide and hydrophobic binding sites, including the sidechains of the residues relevant for binding. The standard nomenclature of the key interacting residues is provided in [25] (PDB identifier 1AOT [38]). All molecular graphics created with YASARA http://www.yasara.org and PovRay http://www.povray.org.