Crystal Structure of IIGP1; A Paradigm for Interferon-Inducible p47 Resistance GTPasesGhosh, A., Uthaiah, R., Howard, J., Herrmann, C., Wolf, E.
(2004) Mol.Cell 15: 727-739
- PubMed: 15350217
- DOI: 10.1016/j.molcel.2004.07.017
- Primary Citation of Related Structures:  1TPZ, 1TQ2, 1TQ4, 1TQD
- PubMed Abstract:
- IIGP1, an interferon-gamma-inducible 47-kDa GTPase of the mouse, showing cooperative enzymatic activity and GTP-dependent multimerization
Uthaiah, R.C.,Praefcke, G.J.K.,Howard, J.C.,Herrmann, C.
(2003) J.Biol.Chem. 278: 29336
Interferon-inducible p47 GTPases are critical mediators of cell-autonomous resistance against several intracellular pathogens. Here we present the first crystal structure of a member of this novel GTPase family, IIGP1, in its nucleotide-free, GDP-, a ...
Interferon-inducible p47 GTPases are critical mediators of cell-autonomous resistance against several intracellular pathogens. Here we present the first crystal structure of a member of this novel GTPase family, IIGP1, in its nucleotide-free, GDP-, and GppNHp-bound form. The structure shows a Ras-like G domain between an N-terminal three-helix bundle and a complex system of C-terminal helices and loops. Sequence comparison and secondary structure prediction suggest the IIGP1 structure to be a valid model for the p47 GTPase family. The IIGP1 crystals contain a noncrystallographic dimer. We show that the dimer is required for cooperative GTP hydrolysis and GTP-dependent oligomerization of IIGP1. We also present the GDP- and GppNHp-bound monomeric structures of two dimer interface mutants. Our structures direct approaches to the analysis of the catalytic mechanism of IIGP1 and provide a coherent basis for structure-function studies aimed at elucidating the mechanistic basis of pathogen resistance caused by these enigmatic GTPases.
Department of Structural Biology, Max Planck Institute for Molecular Physiology, Otto-Hahn-Strasse 11, 44227 Dortmund, Germany.