1d5t
GUANINE NUCLEOTIDE DISSOCIATION INHIBITOR, ALPHA-ISOFORMGUANINE NUCLEOTIDE DISSOCIATION INHIBITOR, ALPHA-ISOFORM
Structural highlights
FunctionGDIA_BOVIN Regulates the GDP/GTP exchange reaction of most Rab proteins by inhibiting the dissociation of GDP from them, and the subsequent binding of GTP to them. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedGuanine nucleotide dissociation inhibitor (GDI) is a 55-kDa protein that functions in vesicular membrane transport to recycle Rab GTPases. We have now determined the crystal structure of bovine alpha-GDI at ultra-high resolution (1.04 A). Refinement at this resolution highlighted a region with high mobility of its main-chain residues. This corresponded to a surface loop in the primarily alpha-helical domain II at the base of alpha-GDI containing the previously uncharacterized sequence-conserved region (SCR) 3A. Site-directed mutagenesis showed that this mobile loop plays a crucial role in binding of GDI to membranes and extraction of membrane-bound Rab. This domain, referred to as the mobile effector loop, in combination with Rab-binding residues found in the multi-sheet domain I at the apex of alpha-GDI may provide flexibility for recycling of diverse Rab GTPases. We propose that conserved residues in domains I and II synergize to form the functional face of GDI, and that domain II mediates a critical step in Rab recycling during vesicle fusion. A new functional domain of guanine nucleotide dissociation inhibitor (alpha-GDI) involved in Rab recycling.,Luan P, Heine A, Zeng K, Moyer B, Greasely SE, Kuhn P, Balch WE, Wilson IA Traffic. 2000 Mar;1(3):270-81. PMID:11208110[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences |
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