Protein Domain : IRG-type guanine nucleotide-binding (G) domain IPR030385

Type	Domain
Description	The P-loop guanosine triphosphatases (GTPases) control a multitude of biological processes, ranging from cell division, cell cycling,and signal transduction, to ribosome assembly and protein synthesis. GTPases exert their control by interchanging between an inactive GDP-bound state andan active GTP-bound state, thereby acting as molecular switches. The common denominator of GTPases is the highly conserved guanine nucleotide-binding (G)domain that is responsible for binding and hydrolysis of guanine nucleotides.The p47 or immunity-related GTPases (IRG) are at least as old as the vertebrates. The IRG proteins are an essential resistance system in the mousefor immunity against pathogens that enter the cell via a vacuole. Despite its importance for the mouse, the IRG resistance system is absent from humansbecause it has been lost during the divergent evolution of the primates. The IRG proteins appear to be accompanied phylogenetically by homologous proteins,named 'quasi IRG' (IRGQ) proteins, that probably lack nucleotide binding or hydrolysis function, and that may form regulatory heterodimers with functionalIRG proteins. The region of lowest similarity is in the G domain, and conserved GTP-binding motifs are lacking [, , ].
Short Name	G_IRG_dom