3RLE: Crystal Structure Of Grasp55 Grasp Domain (residues 7-208)

Biogenesis of the ribbon-like membrane network of the mammalian Golgi requires membrane tethering by the conserved GRASP domain in GRASP65 and GRASP55, yet the tethering mechanism is not fully understood. Here, we report the crystal structure of the GRASP55 GRASP domain, which revealed an unusual arrangement of two tandem PDZ folds that more closely resemble prokaryotic PDZ domains. Biochemical and functional data indicated that the interaction between the ligand-binding pocket of PDZ1 and an internal ligand on PDZ2 mediates the GRASP self-interaction, and structural analyses suggest that this occurs via a unique mode of internal PDZ ligand recognition. Our data uncover the structural basis for ligand specificity and provide insight into the mechanism of GRASP-dependent membrane tethering of analogous Golgi cisternae.
PDB ID: 3RLEDownload
MMDB ID: 90360
PDB Deposition Date: 2011/4/19
Updated in MMDB: 2011/05
Experimental Method:
x-ray diffraction
Resolution: 1.65  Å
Source Organism:
Similar Structures:
Biological Unit for 3RLE: monomeric; determined by author and by software (PISA)
Molecular Components in 3RLE
Label Count Molecule
Protein (1 molecule)
Golgi Reassembly-stacking Protein 2(Gene symbol: GORASP2)
Molecule annotation
* Click molecule labels to explore molecular sequence information.

Citing MMDB