PROSITE documentation PDOC51714
Bms1-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.

Bms1p and Tsr1p represent a new family of factors required for ribosome biogenesis. They are each independently required for 40S ribosomal subunit biogenesis. Bms1p, a protein required for pre-rRNA processing, contains an evolutionarily conserved G domain with five conserved polypeptide loops designated G1 through G5, which form contact sites with the guanine nucleotide or coordinate the Mg(2+) ion. Sequences ressembling G1 (consensus [GA]-x(4)-G-K-[ST]; also known as a P-loop), G4 (consensus [NT]-K-x-D), and G5 (consensus S-[AG] are present in all Bms1 proteins, and either fully conform with the consensus or contain, at most, single conservative substitutions. The G2 motif (consensus G-P-[IV]-T) contains a T residue involved in the coordination of the Mg(2+) required for GTP hydrolysis. The G3 motif diverges from the consensus found in G proteins, D-x(2)-G; however, the D residue is replaced with the conserved E residue. In contrast, Tsr1p lacks a P-loop and is not predicted to bind GTP. It functions at a later step of 40S ribosome production, possibly in assembly and/or export of 43S pre-ribosomal subunits to the cytosol [1,2,3].

The Bms1-type G domain has a small GTPase-like fold (see <PDB:5IW7>) [1].

The profile we developed covers the entire Bms1-type G domain.

Last update:

May 2020 / Profile and text revised.


Technical section

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

G_BMS1, PS51714; Bms1-type guanine nucleotide-binding (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

2AuthorsWegierski T. Billy E. Nasr F. Filipowicz W.
TitleBms1p, a G-domain-containing protein, associates with Rcl1p and is required for 18S rRNA biogenesis in yeast.
SourceRNA 7:1254-1267(2001).
PubMed ID11565748

3AuthorsGelperin D. Horton L. Beckman J. Hensold J. Lemmon S.K.
TitleBms1p, a novel GTP-binding protein, and the related Tsr1p are required for distinct steps of 40S ribosome biogenesis in yeast.
SourceRNA 7:1268-1283(2001).
PubMed ID11565749

4AuthorsMcCaughan U.M. Jayachandran U. Shchepachev V. Chen Z.A. Rappsilber J. Tollervey D. Cook A.G.
TitlePre-40S ribosome biogenesis factor Tsr1 is an inactive structural mimic of translational GTPases.
SourceNat. Commun. 7:11789-11789(2016).
PubMed ID27250689

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