Fig 5. Schematic visualization of the SH3-domain and sequence-alignment of the C-terminal SH3-domains of the ANK54RD-binders identified in the screen.

Secondary structural elements of BTK-SH3-domain and homology alignment of the last 20-amino-acids of the human SH3-domains, according to Kärkkäinen [25] database. The NCF1, BZRAP1 and SH3KBP1 proteins contain more than one SH3-domain and the sequence corresponds to the SH3-domain binding to ANKRD54. SNY-amino-acids create a right-handed 3₁₀ helix [27]. *The biotinylated synthetic BTK-peptide (22-aa) reported in [9] was used as bait for the interaction with endogenous ANKRD54. **The TXK/RLK-SH3 was not identified in this screening, although ANKRD54 influenced the nucleocytoplasmic shuttling of full-length TXK [9].