Rab GDI protein (IPR000806)
Short name: RabGDI
Overlapping homologous superfamilies
- FAD/NAD(P)-binding domain superfamily (IPR036188)
- GDP dissociation inhibitor (IPR018203)
- Rab GDI protein (IPR000806)
Rab proteins, a family of small Ras-related GTP-binding proteins, are involved in regulation of intracellular vesicle trafficking [PMID: 7585614]. Rab GDP dissociation inhibitor (GDI) forms a soluble complex with Rab proteins, thereby preventing exchange of GDP for GTP. Rab GDI exists in several isoforms, and belongs to the TCD/MRS6 family of GDP dissociation inhibitors.
The crystal structure of the bovine alpha-isoform of Rab GDI has been determined to a resolution of 1.81A [PMID: 8609986]. The protein is composed of two main structural units: a large complex multi-sheet domain I, and a smaller alpha-helical domain II.
The structural organisation of domain I is closely related to FAD-containing monooxygenases and oxidases [PMID: 8609986]. Conserved regions common to GDI and the choroideraemia gene product, which delivers Rab to catalytic subunits of Rab geranylgeranyltransferase II, are clustered on one face of the domain [PMID: 7585614]. The two most conserved regions form a compact structure at the apex of the molecule; site-directed mutagenesis has shown these regions to play a critical role in the binding of Rab proteins [PMID: 8609986].
- PR00892 (RABGDI)