Schematic diagrams of the C-SRC versus V-SRC proteins. Note that V-SRC has a carboxy-terminal truncation owing to a frameshift (jagged line) relative to C-SRC. This truncation removes Y527, the most abundant phosphotyrosine in C-SRC. Instead, the most abundant phosphotyrosine in V-SRC is Y416, a residue that is not highly phosphorylated in C-SRC. (SH) SRC homology domain, (Myr) myristoylation. Curved line, plasma membrane. (Adapted from Rosenberg NJ, Jolicoeur P. 1997. In Retroviruses (ed. Coffin JD, et al.), Chapter 10, Fig. 11, © Cold Spring Harbor Laboratory Press.)