Download MendeleyCrystal structure of human GGA1 GAT domain complexed with the GAT-binding domain of Rabaptin5.
Zhu, G., Zhai, P., He, X., Wakeham, N., Rodgers, K., Li, G., Tang, J., Zhang, X.C.(2004) EMBO J 23: 3909-3917
- PubMed: 15457209
- DOI: https://doi.org/10.1038/sj.emboj.7600411
- Primary Citation of Related Structures:
1X79 - PubMed Abstract:
GGA proteins coordinate the intracellular trafficking of clathrin-coated vesicles through their interaction with several other proteins. The GAT domain of GGA proteins interacts with ARF, ubiquitin, and Rabaptin5. The GGA-Rabaptin5 interaction is believed to function in the fusion of trans-Golgi-derived vesicles to endosomes. We determined the crystal structure of a human GGA1 GAT domain fragment in complex with the Rabaptin5 GAT-binding domain. In this structure, the Rabaptin5 domain is a 90-residue-long helix. At the N-terminal end, it forms a parallel coiled-coil homodimer, which binds one GAT domain of GGA1. In the C-terminal region, it further assembles into a four-helix bundle tetramer. The Rabaptin5-binding motif of the GGA1 GAT domain consists of a three-helix bundle. Thus, the binding between Rabaptin5 and GGA1 GAT domain is based on a helix bundle-helix bundle interaction. The current structural observation is consistent with previously reported mutagenesis data, and its biological relevance is further confirmed by new mutagenesis studies and affinity analysis. The four-helix bundle structure of Rabaptin5 suggests a functional role in tethering organelles.
Organizational Affiliation:
Crystallography Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA.
