{PDOC51715} {PS51715; G_GB1_RHD3} {BEGIN} *************************************************************** * GB1/RHD3-type guanine nucleotide-binding (G) domain profile * *************************************************************** The P-loop (see ) 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 GB1/RHD3 GTPase family contains a large G domain (~230 amino acids). It is widespread in eukaryotes, but not detectable in bacteria or archaea. One conserved subfamily is typified by the Arabidopsis protein root hair defective 3 (RHD3), whose othologs are present in all crown group eukaryotes. The other subfamily is typified by the interferon gamma-induced antiviral GB1 protein that is conserved in animals. The other GTPases of this subfamily are the brain finger proteins (BFPs), in which the GTPase domain is combined with an N-terminal RING finger domain (see ), which implicates these proteins in ubiquitin-mediated signaling. Most members of this family have a large C-terminal, alpha-helical extension that probably participates in protein-protein interactions. The GB1/RHD3-type G domain has a low intrinsic affinity for nucleotide and often depends on nucleotide-dependent homodimerization to facilitate GTP hydrolysis [1,2,3,4,5,6]. The large GB1/RHD3-type G domain consists of a six-stranded beta-sheet surrounded by eight helices (see ). It contains the conserved sequence elements of GTP-binding proteins with modifications [2,4,6]. The profile we developed covers the entire GB1/RHD3-type G domain. -Sequences known to belong to this class detected by the profile: ALL. -Other sequence(s) detected in Swiss-Prot: NONE. -Last update: April 2014 / First entry. [ 1] Leipe D.D., Wolf Y.I., Koonin E.V., Aravind L. "Classification and evolution of P-loop GTPases and related ATPases." J. Mol. Biol. 317:41-72(2002). PubMed=11916378; DOI=10.1006/jmbi.2001.5378 [ 2] Prakash B., Praefcke G.J.K., Renault L., Wittinghofer A., Herrmann C. "Structure of human guanylate-binding protein 1 representing a unique class of GTP-binding proteins." Nature 403:567-571(2000). PubMed=10676968; DOI=10.1038/35000617 [ 3] Prakash B., Renault L., Praefcke G.J.K., Herrmann C., Wittinghofer A. "Triphosphate structure of guanylate-binding protein 1 and implications for nucleotide binding and GTPase mechanism." EMBO J. 19:4555-4564(2000). PubMed=10970849; DOI=10.1093/emboj/19.17.4555 [ 4] Ghosh A., Praefcke G.J.K., Renault L., Wittinghofer A., Herrmann C. "How guanylate-binding proteins achieve assembly-stimulated processive cleavage of GTP to GMP." Nature 440:101-104(2006). PubMed=16511497; DOI=10.1038/nature04510 [ 5] Stefano G., Renna L., Moss T., McNew J.A., Brandizzi F. "In Arabidopsis, the spatial and dynamic organization of the endoplasmic reticulum and Golgi apparatus is influenced by the integrity of the C-terminal domain of RHD3, a non-essential GTPase." Plant J. 69:957-966(2012). PubMed=22082223; DOI=10.1111/j.1365-313X.2011.04846.x [ 6] Byrnes L.J., Sondermann H. "Structural basis for the nucleotide-dependent dimerization of the large G protein atlastin-1/SPG3A." Proc. Natl. Acad. Sci. U.S.A. 108:2216-2221(2011). PubMed=21220294; DOI=10.1073/pnas.1012792108 -------------------------------------------------------------------------------- PROSITE is copyrighted by the SIB Swiss Institute of Bioinformatics and distributed under the Creative Commons Attribution-NonCommercial-NoDerivatives (CC BY-NC-ND 4.0) License, see https://prosite.expasy.org/prosite_license.html -------------------------------------------------------------------------------- {END}