1UPT: Structure of a Complex of the Golgin-245 Grip Domain With Arl1

Golgins are large coiled-coil proteins that play a role in Golgi structure and vesicle traffic. The Arf-like GTPase Arl1 regulates the translocation of GRIP domain-containing golgins to Golgi membranes. We report here the 1.7 A resolution structure of human Arl1-GTP in a complex with the GRIP domain of golgin-245. The structure reveals that the GRIP domain consists of an S-shaped arrangement of three helices. The domain forms a homodimer that binds two Arl1-GTPs using two helices from each monomer. The structure is consistent with golgin-245 forming parallel coiled-coils and suggests how Arl1-GTP/GRIP complexes interact with Golgi membranes via the N termini of Arl1-GTP and the C-terminal tails of the GRIP domains. In cells, bivalent association with Arl1-GTP would increase residence time of the golgins on Golgi membranes. Despite no conservation of sequence, topology, or even helical direction, several other effectors form similar interactions with small GTPases via a pair of alpha helices, suggesting a common structural basis for effector recognition.
PDB ID: 1UPTDownload
MMDB ID: 25560
PDB Deposition Date: 2003/10/12
Updated in MMDB: 2003/12
Experimental Method:
x-ray diffraction
Resolution: 1.7  Å
Source Organism:
Similar Structures:
Biological Unit for 1UPT: tetrameric; determined by author and by software (PQS)
Molecular Components in 1UPT
Label Count Molecule
Proteins (4 molecules)
Adp-ribosylation Factor-like Protein 1(Gene symbol: ARL1)
Molecule annotation
Golgi Autoantigen, Golgin Subfamily a Member 4(Gene symbol: GOLGA4)
Molecule annotation
Chemicals (4 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB