PROSITE documentation PDOC51705HflX-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 [1,2,3].
Within the translation factor-related (TRAFAC) class of P-loop GTPases, the HflX-type is a widely distributed family of GTPases that interact with the large ribosomal subunit. The broad phylogenetic distribution pattern of HflX GTPases in Bacteria, Archaea, and Eukaryotes (including human) suggests a basic cellular function for this protein family.
The HflX-type G domain is composed of six β-strands and five α-helices (see <PDB:2QTF>) [2]. It consists of the following conserved sequence motifs: the G1 motif (or P-loop), consensus GX4GK(S/T), which is responsible for interacting with the α and β-phosphates of nucleotide di- and triphosphates; the G2 variable effector loop (DXnT); the G3 motif (DX2G), which interacts with the γ-phosphate of nucleotide triphosphates; and the G4 motif (NKXD), which conveys specificity for guanine nucleotides through hydrogen bonding to the base [3].
The profile we developed covers the entire HflX-type G domain.
Last update:February 2014 / First entry.
-------------------------------------------------------------------------------
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 | Wu H. Sun L. Blombach F. Brouns S.J.J Snijders A.P.L: Lorenzen K. van den Heuvel R.H.H. Heck A.J.R. Fu S. Li X. Zhang X.C. Rao Z. van der Oost J. |
| Title | Structure of the ribosome associating GTPase HflX. | |
| Source | Proteins 78:705-713(2010). | |
| PubMed ID | 19787775 | |
| DOI | 10.1002/prot.22599 |
| 3 | Authors | Shields M.J. Fischer J.J. Wieden H.-J. |
| Title | Toward understanding the function of the universally conserved GTPase HflX from Escherichia coli: a kinetic approach. | |
| Source | Biochemistry 48:10793-10802(2009). | |
| PubMed ID | 19824612 | |
| DOI | 10.1021/bi901074h |
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 prosite_license.html.
View entry in original PROSITE document format
View entry in raw text format (no links)