1T91: Crystal Structure Of Human Small Gtpase Rab7(Gtp)

Rab7 regulates vesicle traffic from early to late endosomes, and from late endosomes to lysosomes. The crystal structure of Rab7-GTP in complex with the Rab7 binding domain of RILP reveals that Rab7 interacts with RILP specifically via two distinct areas, with the first one involving the switch and interswitch regions and the second one consisting of RabSF1 and RabSF4. Disruption of these interactions by mutations abrogates late endosomal/lysosomal targeting of Rab7 and RILP. The Rab7 binding domain of RILP forms a coiled-coil homodimer with two symmetric surfaces to interact with two separate Rab7-GTP molecules, forming a dyad configuration of Rab7-RILP(2)-Rab7. Mutations that disrupt RILP dimerization also abolish its interactions with Rab7-GTP and late endosomal/lysosomal targeting, suggesting that the dimeric form of RILP is a functional unit. Structural comparison suggests that the combined use of RabSF1 and RabSF4 with the switch regions may be a general mode of action for most Rab proteins in regulating membrane trafficking.
PDB ID: 1T91Download
MMDB ID: 33312
PDB Deposition Date: 2004/5/14
Updated in MMDB: 2012/11
Experimental Method:
x-ray diffraction
Resolution: 1.9  Å
Source Organism:
Similar Structures:
Biological Unit for 1T91: monomeric; determined by author
Molecular Components in 1T91
Label Count Molecule
Protein (1 molecule)
Ras-related Protein Rab-7(Gene symbol: RAB7A)
Molecule annotation
Chemicals (2 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB