Fig. 13

Protein docking models for the 14-3-3-Eag1-Cul7 complex. Homology modeling of the Cul7 protein complex was based on the structures of cullin 1 (PDB: 1LDK), Skp1-Fbw7 complex (PDB: 2OVP), E2 ubiquitin-conjugating enzyme (PDB: 3CEG), Doc1 homology domain (PDB: 1GQP), and CPH domain (PDB: JNG). A Interaction of 14-3-3θ homodimer (aqua, green) with the Cul7 (tangerine)-Skp1 (orange)-Fbw8 (saffron)-Rbx1 (olive)-E2 (pumpkin) protein complex. One 14-3-3θ subunit (green) may directly contact a Cul7 loop region between the DOC domain and C-terminal domain, whereas the other 14-3-3θ subunit (aqua) is modeled as a binding partner of the adaptor protein Skp1. B Ternary organization of 14-3-3θ homodimer, Cul7 protein complex, and the PAS domain/CNBHD from three Eag1 subunits (violet, burgundy, blue). The Cul7 complex appears to exclusively bind to a single Eag1 subunit (burgundy), with the Cul7 C-terminal domain sitting on the surface of the Eag1 PAS domain, and the substrate-targeting subunit Fbw8 directly contacting the Eag1 CNBHD. As in Fig. 13, 14-3-3θ homodimer (aqua, green) interacts with the N-linker (violet)/CNBHD (burgundy)/post-CNBHD (blue) from three distinct Eag1 subunits, respectively. Also shown are two sets of intersubunit PAS domain-CNBHD interaction between neighboring Eag1 subunits (violet-burgundy; burgundy-blue). C Transmembrane, extracellular, and intracellular views of four Cul7 protein complexes, four 14-3-3θ homodimers, and the Eag1 tetramer (violet, burgundy, blue, salmon) at the plasma membrane. The docking models in (A) and (B) are equivalent to the enlargement of a portion of the transmembrane and intracellular views, respectively