Guanine Nucleotide Dissociation Inhibitor (GDI)

IUCr Abstract

Crystallization

47. Shalk I.J., Stura E.A., Matteson J., Wilson, I.A., Balch E.E. (1994) Crystallization and preliminary crystallographic data for Rab guanine nucleotide dissociation inhibitor (RabGDI) from Bovine Brain. Journal of Molecular Biology, 244, 469-473.

Abstract: X-ray quality crystals of Rab guanine nucleotide dissociation inhibitor (RabGDI) from bovine brain expressed in Escherichia coli have been obtained from 1.73 M ammonium sulfate. The crystals are prismatic long rods and belong to the monoclinic space group P21 with approximate cell dimensions a = 91.9 Å, b = 43.5 Å, c = 63.2 Å, beta = 104.5° and one molecule per asymmetric unit. The crystals are stable in the X-ray beam and diffract to at least 2.3 Å. Reverse screening, streak seeding and macroseeding methods were used to obtain and improve the crystals.

Crystallization conditions

Structure

55. Shalk, I., Zeng, K., Wu, S.-K., Stura, E.A., Matteson J., Huang M., Tandon, A., Wilson, I.A. and Balch, W.E. (1996) Structure and mutational analysis of Rab GDP-dissociation inhibitor. Nature 381:42-48.

Abstract: The crystal structure of the bovine alpha-isoform of guanine nucleotide dissociation inhibitor (GDI), which functions in vesicle membrane transport to recycle and regulate Rab GTPases, has been determined to a resolution of 1.81 Å. GDI is constructed of two main structural units, a large complex multi-sheet domain I and a smaller a-helical domain II. The fold organization of domain I is surprisingly closely related to FAD-containing mono-oxygenases and oxidases. Sequqnce-conserved regions comon to GDI and the choroideremia gene product, which delivers Rab to catalytic subunits of Rab geranyltransferase II, are clustered on one face of the molecule.The two most sequqnce-conserved regions, which form a compact structure at the apex of GDI, are shown by site directed mutagenesis to play a critical role in the binding of Rab proteins.