Under conditions of increased detergent stringency Sam 68 , Wiskott Aldrich Syndrome protein , and hnRNP K , but not Cbl and Fyn , were bound to the Itk SH 3 domain . ^^^ By examining the ability of different SH 3 domains to interact with deletion variants of Sam 68 and WASP , we demonstrated that the Itk SH 3 domain and the SH 3 domains of Src family kinases bind to overlapping but distinct sets of proline rich regions in Sam 68 and WASP . . ^^^
Formation of this intramolecular SH 3 ligand complex prevents the Itk SH 3 domain and proline rich region from interacting with their respective protein ligands , Sam 68 and Grb 2 . ^^^