PROSITE documentation PDOC51720
AIG1-type guanine nucleotide-binding (G) domain profile


The P-loop (see <PDOC00017>) 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 TRAFAC (translation factor related) class AIG1/Toc34/Toc159-like paraseptin GTPase family contains the following subfamilies [1]:

  • The GTPases of immunity-associated protein (GIMAP)/immune-associated nucleotide-binding protein (IAN) subfamily is conserved among vertebrates and angiosperm plants and has been postulated to regulate apoptosis, particularly in context with diseases such as cancer, diabetes, and infections. The function of GIMAP/IAN GTPases has been linked to self defense in plants and to the development of T cells in vertebrates [2,3].
  • Plant-specific Toc (translocon at the outer envelope membrane of chloroplasts) proteins. Toc proteins function as integral components of the chloroplast protein import machinery. The Toc translocon contains the two membrane-bound GTPases Toc33/34 and Toc 159, which expose their G domains to the cytosol and recognize and then deliver precursor proteins through the translocation pore Toc75 [4,5].

The GIMAP/IAN GTPases contain a avrRpt2 induced gene 1 (AIG1)-type G domain that exhibits the five motifs G1-G5 characteristic for GTP/GDP-binding proteins. In addition, the AIG-type G domain contains a unique, highly conserved, hydrophobic motif between G3 and G4. It has a divergent version of the guanine recognition motif (G4) at the end of the core strand 5 and an additional helix α6 at the C-terminus. The AIG1-type G domain contains a central β-sheet sandwiched by two layers of α-helices (see <PDB:2XTN>).

The profile we developed covers the entire AIG1-type G domain.

Last update:

June 2020 / Profile revised.


Technical section

PROSITE method (with tools and information) covered by this documentation:

G_AIG1, PS51720; AIG1-type G domain profile  (MATRIX)


1AuthorsLeipe D.D. Wolf Y.I. Koonin E.V. Aravind L.
TitleClassification and evolution of P-loop GTPases and related ATPases.
SourceJ. Mol. Biol. 317:41-72(2002).
PubMed ID11916378

2AuthorsKruecken J. Schroetel R.M. Mueller I.U. Saidani N. Marinovski P. Benten W.P. Stamm O. Wunderlich F.
TitleComparative analysis of the human gimap gene cluster encoding a novel GTPase family.
SourceGene 341:291-304(2004).
PubMed ID15474311

3AuthorsSchwefel D. Froehlich C. Eichhorst J. Wiesner B. Behlke J. Aravind L. Daumke O.
TitleStructural basis of oligomerization in septin-like GTPase of immunity-associated protein 2 (GIMAP2).
SourceProc. Natl. Acad. Sci. U.S.A. 107:20299-20304(2010).
PubMed ID21059949

4AuthorsYeh Y.-H. Kesavulu M.M. Li H.-M. Wu S.-Z. Sun Y.-J. Konozy E.H.E.
TitleHsiao C.-D. Dimerization is important for the GTPase activity of chloroplast translocon components atToc33 and psToc159.
SourceJ. Biol. Chem. 282:13845-13853(2007).
PubMed ID17337454

5AuthorsKoenig P. Oreb M. Hoefle A. Kaltofen S. Rippe K. Sinning I. Schleiff E. Tews I.
TitleThe GTPase cycle of the chloroplast import receptors Toc33/Toc34: implications from monomeric and dimeric structures.
SourceStructure 16:585-596(2008).
PubMed ID18400179

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