The src gene product is a nonreceptor protein kinase called pp60src. This protein is a tyrosine protein kinase that phosphorylates target proteins at specific tyrosine residues. This tyrosine protein kinase is an integral member of a signal transduction pathway leading to the transition from G2 to M phase. The pp60src protein is phosphorylated by an upstream kinase. The phosphorylation changes the conformation of the protein such that its kinase domain is exposed and is able to then phosphorylate downstream target proteins.
How might a point mutation create a hyperactive form of pp60src (the src gene is a proto-oncogene)?