PROSITE documentation PDOC51714Bms1-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.
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PROSITE method (with tools and information) covered by this documentation:
| 1 | Authors | Leipe D.D. Wolf Y.I. Koonin E.V. Aravind L. |
| Title | Classification and evolution of P-loop GTPases and related ATPases. | |
| Source | J. Mol. Biol. 317:41-72(2002). | |
| PubMed ID | 11916378 | |
| DOI | 10.1006/jmbi.2001.5378 |
| 2 | Authors | Wegierski T. Billy E. Nasr F. Filipowicz W. |
| Title | Bms1p, a G-domain-containing protein, associates with Rcl1p and is required for 18S rRNA biogenesis in yeast. | |
| Source | RNA 7:1254-1267(2001). | |
| PubMed ID | 11565748 |
| 3 | Authors | Gelperin D. Horton L. Beckman J. Hensold J. Lemmon S.K. |
| Title | Bms1p, a novel GTP-binding protein, and the related Tsr1p are required for distinct steps of 40S ribosome biogenesis in yeast. | |
| Source | RNA 7:1268-1283(2001). | |
| PubMed ID | 11565749 |
| 4 | Authors | McCaughan U.M. Jayachandran U. Shchepachev V. Chen Z.A. Rappsilber J. Tollervey D. Cook A.G. |
| Title | Pre-40S ribosome biogenesis factor Tsr1 is an inactive structural mimic of translational GTPases. | |
| Source | Nat. Commun. 7:11789-11789(2016). | |
| PubMed ID | 27250689 | |
| DOI | 10.1038/ncomms11789 |
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