Our deepest condolences go out to his family and friends, and to all those who had the privilege of working with him. Rest in peace, Amos. Your work will live on long after you are gone.
PROSITE documentation PDOC51705HflX-type guanine nucleotide-binding (G) domain profile
View entry in original PROSITE document format
View entry in raw text format (no links)
PURL: https://purl.expasy.org/prosite/documentation/PDOC51705
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.