The fifth SH3 domain of TKS5 is required for binding to FGD1. Lysates of MDA-MB-231 cells expressing the indicated GFP-tagged constructs were immunoprecipitated with anti-GFP nanobody. Bound proteins were analyzed with FGD1 antibodies (IP). 1% of total lysate was loaded as a control (input). The binding capacity of the different TKS5 constructs to FGD1 is indicated in percentage of wild-type TKS5.