guanosine-diphosphate and Choroideremia

The 1.81 A crystal structure of Rab GDP-dissociation inhibitor (GDI), a protein that plays a critical role in the recycling of Rab GTPases involved in membrane vesicular transport, has been recently determined. Biochemical studies implicate a highly conserved region involved in Rab binding, which is common to both GDI and the evolutionarily-related choroideremia gene product (CHM/REP) required for Rab prenylation. Here, we summarize the mechanisms by which members of the GDI superfamily might function to coordinate events leading to membrane fusion, and we discuss the unexpected, yet striking structural homology of GDI to FAD-binding proteins.

Topics: Adaptor Proteins, Signal Transducing; Alkyl and Aryl Transferases; Amino Acid Sequence; Animals; Binding Sites; Carrier Proteins; Choroideremia; Conserved Sequence; Flavoproteins; GTP-Binding Proteins; Guanine Nucleotide Dissociation Inhibitors; Guanosine Diphosphate; Humans; Models, Molecular; Protein Conformation; rab GTP-Binding Proteins