PROSITE documentation PDOC51883
Obg domain profile


Obg (spo0B-associated GTP-binding) proteins (also known as ObgE, YhbZ and CgtA) are a subfamily of P-loop GTPases, conserved from bacteria to eukaryotes. Like other GTPases, Obg proteins cycle between a GTP-bound ON and a GDP-bound OFF state, thereby controlling cellular processes. Obg proteins have been attributed a host of cellular functions, including roles in essential cellular processes (DNA replication, ribosome maturation) and roles in different stress adaptation pathways (stringent response, sporulation, general stress response). Obg GTPases function in ribosome maturation in eubacteria, mitochondria of yeast and human nuclei. Members of the subfamily display a three-domain arrangement with an N-terminal glycine-rich domain typical for the subfamily (Obg domain), a central G domain (see <PDOC51710>) and a C-terminal domain that is highly variable in length and sequence among Obg proteins from different species. The Obg domain is essential for functioning and correct folding of Obg proteins. It could play a platform or scaffolding role and serve as a structural mimic for nucleic acid [1,2,3,4].

Two regions can be discerned in the Obg domain: a glycine-rich region with six left-handed type II helices connected on one side by long loops, and an eight-stranded β barrel containing an α-helix between the second and third strand (see <PDB:5M04>). This β-barrel makes extensive contacts with the G domain. The Obg domain is a structural mimic of the acceptor arm of the A-site tRNA, which exhibits specific interactions with the ribosomal peptidyl-transferase center [1,2,3,4].

The profile we developed covers the entire Obg domain.

Last update:

January 2019 / First entry.


Technical section

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

OBG, PS51883; Obg domain profile  (MATRIX)


1AuthorsBuglino J. Shen V. Hakimian P. Lima C.D.
TitleStructural and biochemical analysis of the Obg GTP binding protein.
SourceStructure 10:1581-1592(2002).
PubMed ID12429099

2AuthorsKint C. Verstraeten N. Hofkens J. Fauvart M. Michiels J.
TitleBacterial Obg proteins: GTPases at the nexus of protein and DNA synthesis.
SourceCrit. Rev. Microbiol. 40:207-224(2014).
PubMed ID23537324

3AuthorsFeng B. Mandava C.S. Guo Q. Wang J. Cao W. Li N. Zhang Y. Zhang Y. Wang Z. Wu J. Sanyal S. Lei J. Gao N.
TitleStructural and functional insights into the mode of action of a universally conserved Obg GTPase.
SourcePLoS Biol. 12:E1001866-E1001866(2014).
PubMed ID24844575

4AuthorsGkekas S. Singh R.K. Shkumatov A.V. Messens J. Fauvart M. Verstraeten N. Michiels J. Versees W.
TitleStructural and biochemical analysis of Escherichia coli ObgE, a central regulator of bacterial persistence.
SourceJ. Biol. Chem. 292:5871-5883(2017).
PubMed ID28223358

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)