Structure of the SH3 domain of rat endophilin A2

The crystal structure of the SH3 domain of rat endophilin A2 has been determined by the multiwavelength anomalous dispersion method and refined at a resolution of 1.70 angstrom to R and R-free values of 0.196 and 0.217, respectively. The structure adheres to the canonical SH3-domain fold and is highly similar to those of the corresponding domains of endophilins A1 and A3. An intermolecular packing interaction between two molecules in the lattice exploits features that are commonly observed in SH3-domain ligand recognition, including the insertion of a proline side chain into the ligand-binding groove of the protein and the recognition of a basic residue by a cluster of acidic side chains on the RT loop.