Helically-extended SH3 domain (IPR029294)

Short name: hSH3

Overlapping homologous superfamilies

Domain relationships


This domain corresponds to the 70 C-terminal residues of ADAP - Adhesion and de-granulation promoting adapter protein, also known as FYN-binding protein. This domain shows homology to SH3 domains; however, conserved residues of the fold are absent. It thus represents an altered SH3 domain fold. An N-terminal, amphipathic, helix makes extensive contacts to residues of the regular SH3 domain fold thereby creating a composite surface with unusual surface properties. The domain can no longer bind conventional proline-rich peptides [PMID: 15062083]. There are key phosphorylation sites within the two hSH3 domains and it would appear that binding at these sites does not materially affect the folding of these regions although the equilibrium towards the unfolded state may be slightly altered [PMID: 20661443]. Instead, the hSH3 domain functions as a novel lipid interaction domain and can bind acidic lipids such as phosphatidylserine, phosphatidylinositol, phosphatidic acid, and polyphosphoinositides [PMID: 15062083, PMID: 16831444, PMID: 15843031].

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.