IRG-type guanine nucleotide-binding (G) domain (IPR030385)

Short name: G_IRG_dom

Overlapping homologous superfamilies

Domain relationships



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 and an 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 mouse for immunity against pathogens that enter the cell via a vacuole. Despite its importance for the mouse, the IRG resistance system is absent from humans because 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 functional IRG proteins. The region of lowest similarity is in the G domain, and conserved GTP-binding motifs are lacking [PMID: 11916378, PMID: 9862701, PMID: 16277747].

GO terms

Biological Process

No terms assigned in this category.

Molecular Function

GO:0005525 GTP binding

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
PROSITE profiles