WW Domain Binding Protein 2 (WBP2)

The globular WW domain is composed of 38 to 40 semiconserved amino acids shared by proteins of diverse functions including structural, regulatory, and signaling proteins. The domain is involved in mediating protein-protein interactions through the binding of polyproline ligands. WBP2 encodes a WW domain binding protein, which binds to the WW domain of Yes kinase-associated protein by its PY motifs. The function of this protein has not been determined.

Sequence comparison showed no homology between the 2 proteins except in a short proline-rich region containing the invariant residues PPPPY, which the authors designated the PY motif. Wbp1 contains a single PY motif, whereas Wbp2 contains 2 in the forward orientation and 1 in the reverse orientation.