Figure 3. KCC3 proline-rich segment mediates binding to Vav2 SH3-domain.

The proline-rich sequence interacts with a collection of SH3 domains detected after incubation of a biotinylated wild-type peptide (LLNMPGPPRNPEGDE) with a commercially available SH3 domain array (Panomics). Wild-type peptide binds to the second SH3 domain (D2) of the Vav proteins Vav2 and Vav3 but not to the SH3-domain of cortactin. To control for binding specificity of the wild-type peptide on the array, a peptide mutated for two proline residues (LLNMPGQARNPEGDE) was used in parallel experiments.