{PDOC51883}
{PS51883; OBG}
{BEGIN}
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* Obg domain profile *
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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 beta  barrel  containing  an alpha-helix between the second and third
strand (see  <PDB:5M04>). This beta-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.

-Sequences known to belong to this class detected by the profile: ALL.
-Other sequence(s) detected in Swiss-Prot: NONE.
-Last update: January 2019 / First entry.

[ 1] Buglino J., Shen V., Hakimian P., Lima C.D.
     "Structural and biochemical analysis of the Obg GTP binding protein."
     Structure 10:1581-1592(2002).
     PubMed=12429099
[ 2] Kint C., Verstraeten N., Hofkens J., Fauvart M., Michiels J.
     "Bacterial Obg proteins: GTPases at the nexus of protein and DNA
     synthesis."
     Crit. Rev. Microbiol. 40:207-224(2014).
     PubMed=23537324; DOI=10.3109/1040841X.2013.776510
[ 3] Feng 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.
     "Structural and functional insights into the mode of action of a
     universally conserved Obg GTPase."
     PLoS Biol. 12:E1001866-E1001866(2014).
     PubMed=24844575; DOI=10.1371/journal.pbio.1001866
[ 4] Gkekas S., Singh R.K., Shkumatov A.V., Messens J., Fauvart M.,
     Verstraeten N., Michiels J., Versees W.
     "Structural and biochemical analysis of Escherichia coli ObgE, a
     central regulator of bacterial persistence."
     J. Biol. Chem. 292:5871-5883(2017).
     PubMed=28223358; DOI=10.1074/jbc.M116.761809

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