1x79
From Proteopedia
Crystal structure of human GGA1 GAT domain complexed with the GAT-binding domain of Rabaptin5
Overview
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.
About this Structure
1X79 is a Protein complex structure of sequences from Homo sapiens. Full crystallographic information is available from OCA.
Reference
Crystal 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 XC, EMBO J. 2004 Oct 13;23(20):3909-17. Epub 2004 Sep 30. PMID:15457209 Page seeded by OCA on Sat May 3 14:39:28 2008
