1d5t
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GUANINE NUCLEOTIDE DISSOCIATION INHIBITOR, ALPHA-ISOFORM
OverviewOverview
Guanine 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.
About this StructureAbout this Structure
1D5T is a Single protein structure of sequence from Bos taurus with SO4 as ligand. Full crystallographic information is available from OCA.
ReferenceReference
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
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