|PROSITE documentation PDOC50909 [for PROSITE entry PS50909]|
The GAT domain is a region of homology of ~130 residues, which is found in eukaryotic GGAs (for Golgi-localized, γ ear-containing ADP ribosylation factor (ARF)-binding proteins) and vertebrate TOMs (for target of myb). The GAT domain is found in its entirety only in GGAs, although, at the C-terminus it shares partial sequence similarity with a short region of TOMs. The GAT domain is found in association with other domains, such as VHS (see <PDOC50179>) and GAE (see <PDOC50180>). The GAT domain of GGAs serves as a molecular anchor of GGA to trans-Golgi network (TGN) membranes via its interaction with the GTP-bound form of a member of the ARF family of small GTPases and can bind specifically to the Rab GTPase effector rabaptin5 and to ubiquitin [1,2,3,4,5].
The GGA-GAT domain possesses an all α-helical structure, composed of four helices arranged in a somewhat unusual topology, which has been called the helical paper clip (see <PDB:1NAF>). The overall structure shows that the GAT domain has an elongated shape, in which the longest helix participates in two small independent subdomains: an N-terminal helix-loop-helix hook and a C-terminal three-helix bundle. The hook subdomain has been shown to be both necessary and sufficient for ARF-GTP binding and Golgi targeting of GGAs. The N-terminal hook subdomain contains a hydrophobic patch, which is found to interact directly with ARF . It has been proposed that this interaction might stabilize the hook subdomain . The C-terminal three-helix bundle is involved in the binding with Rabaptin5 and ubiquitin .
The profile we developed covers the entire GAT domain.Last update:
November 2004 / First entry.
PROSITE method (with tools and information) covered by this documentation:
|1||Authors||Dell'Angelica E.C. Puertollano R. Mullins C. Aguilar R.C. Vargas J.D. Hartnell L.M. Bonifacino J.S.|
|Source||J. Cell Biol. 149:81-94(2000).|
|2||Authors||Puertollano R. Randazzo P.A. Presley J.F. Hartnell L.M. Bonifacino J.S.|
|Title||The GGAs promote ARF-dependent recruitment of clathrin to the TGN.|
|3||Authors||Collins B.M. Watson P.J. Owen D.J.|
|Title||The structure of the GGA1-GAT domain reveals the molecular basis for ARF binding and membrane association of GGAs.|
|Source||Dev. Cell 4:321-332(2003).|
|4||Authors||Shiba T. Kawasaki M. Takatsu H. Nogi T. Matsugaki N. Igarashi N. Suzuki M. Kato R. Nakayama K. Wakatsuki S.|
|Title||Molecular mechanism of membrane recruitment of GGA by ARF in lysosomal protein transport.|
|Source||Nat. Struct. Biol. 10:386-393(2003).|
|5||Authors||Zhu G. Zhai P. He X. Wakeham N. Rodgers K. Li G. Tang J. Zhang X.C.|
|Title||Crystal structure of human GGA1 GAT domain complexed with the GAT-binding domain of Rabaptin5.|
|Source||EMBO J. 23:3909-3917(2004).|