 The N-terminal SH3 domain binds to proline-rich peptides and can bind to the Ras-guanine exchange factor SOS.The C-terminal SH3 domain binds to peptides conforming to a P-X-I/L/V/-D/N-R-X-X-K-P motif that allows it to specifically bind to proteins such as Gab-1.Grb2 has been shown to interact with