AP-2 adaptors regulate clathrin-bud formation at the cell surface by recruiting clathrin trimers to the plasma membrane and by selecting certain membrane proteins for inclusion within the developing clathrin-coat structure. These functions are performed by discrete subunits of the adaptor heterotetramer. The carboxyl-terminal appendage of the AP-2 α subunit appears to regulate the translocation of several endocytic accessory proteins to the bud site. We have determined the crystal structure of the α appendage at 1.4-Å resolution by multiwavelength anomalous diffraction phasing. It is composed of two distinct structural modules, a β-sandwich domain and a mixed α-β platform domain. Structure-based mutagenesis shows that alterations to the molecular surface of a highly conserved region on the platform domain differentially affect associations of the appendage with amphiphysin, eps15, epsin, and AP180, revealing a common protein-binding interface.
|Number of pages||6|
|Journal||Proceedings of the National Academy of Sciences of the United States of America|
|State||Published - Aug 3 1999|