Fig. 1. Adaptor structure and interacting proteins. (A) Proposed AP-1 subunit organisation based on two hybrid studies and the structure of AP-2 and location of sites for interaction with binding partners. AP-2 is so far the only clathrin adaptor whose complete structure has been determined. (B) The 3D structure of the subunits of AP-2 (Collins et al., 2002) illustrates the compact nature of the large subunit body domains in association with the µ2 and 2 chain. The appendages of the ß2 and subunits, determined independently (Owen et al., 2000; Traub et al., 1999) are shown in the left and right box, respectively for comparison with the 1 appendage in panel C. (C) Regions of the 1 subunit that interact with cytoplasmic proteins involved in coat recruitment. The 3D structure of the -ear/appendage domain is shown (Nogi et al., 2002). (D) The modular domain organisation of GGA and interacting proteins, illustrating the 3D structure of the VHS domain in association with the dileucine motif from MPR (Misra et al., 2002; Shiba et al., 2002).