SH3 Domain Containing Protein 21 (SH3D21)

SH3D21 contains three SH3 domains. These domains are located near the N-terminus of the protein. In humans, these SH3 domains have a common amino acid sequence Asp-Glu-Leu. This sequence motif is also conserved in other species. SH3D21 has been found to interact with Adenylate Kinase 2, Artemin, and Importin 13. The human protein has two isoforms and no paralogs. The second isoform is 645 amino acids long and is identical to the first isoform, except it is missing the first 111 amino acids. Due to this, the second isoform is missing the first, and half of the second, N-terminal SH3 domain. Secondary structure analysis of SH3D21 indicates a long alpha helical structure near the C-terminus. SH3D21 is predicted to have many phosphorylation sites and multiple sumolyation sites throughout the entirety of the protein.