Figure 3.

Schematic representation of Src in the low activity state (left) and the active state (right). In the low activity configuration, the SH2 domain binds the phosphorylated C-terminal Tyr⁵³⁰, while the SH3 domain interacts with the linker domain, promoting a relative “closed” conformation. In the active configuration, SH2 and SH3 domains are released from the intramolecular interactions with autophosphorylation of Tyr⁴¹⁹, which enhances the catalytic activity of Src. Activation of Src is mediated by activation of transmembrane tyrosine receptors (RTK) upon binding the corresponding ligands or, alternatively, by the C-terminal intracellular truncated isoforms.