Structural highlights
Function
[GGA1_HUMAN] Plays a role in protein sorting and trafficking between the trans-Golgi network (TGN) and endosomes. Mediates the ARF-dependent recruitment of clathrin to the TGN and binds ubiquitinated proteins and membrane cargo molecules with a cytosolic acidic cluster-dileucine (AC-LL) motif.[1]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
GGAs are a family of vesicle-coating regulatory proteins that function in intracellular protein transport. A GGA molecule contains four domains, each mediating interaction with other proteins in carrying out intracellular transport. The GAT domain of GGAs has been identified as the structural entity that binds membrane-bound ARF, a molecular switch regulating vesicle-coat assembly. It also directly interacts with rabaptin5, an essential component of endosome fusion. A 2.8 A resolution crystal structure of the human GGA1 GAT domain is reported here. The GAT domain contains four helices and has an elongated shape with the longest dimension exceeding 80 A. Its longest helix is involved in two structural motifs: an N-terminal helix-loop-helix motif and a C-terminal three-helix bundle. The N-terminal motif harbors the most conservative amino acid sequence in the GGA GAT domains. Within this conserved region, a cluster of residues previously implicated in ARF binding forms a hydrophobic surface patch, which is likely to be the ARF-binding site. In addition, a structure-based mutagenesis-biochemical analysis demonstrates that the C-terminal three-helix bundle of this GAT domain is responsible for the rabaptin5 binding. These structural characteristics are consistent with a model supporting multiple functional roles for the GAT domain.
Crystal structure of the human GGA1 GAT domain.,Zhu G, Zhai P, He X, Terzyan S, Zhang R, Joachimiak A, Tang J, Zhang XC Biochemistry. 2003 Jun 3;42(21):6392-9. PMID:12767220[2]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Puertollano R, Randazzo PA, Presley JF, Hartnell LM, Bonifacino JS. The GGAs promote ARF-dependent recruitment of clathrin to the TGN. Cell. 2001 Apr 6;105(1):93-102. PMID:11301005
- ↑ Zhu G, Zhai P, He X, Terzyan S, Zhang R, Joachimiak A, Tang J, Zhang XC. Crystal structure of the human GGA1 GAT domain. Biochemistry. 2003 Jun 3;42(21):6392-9. PMID:12767220 doi:10.1021/bi034334n
