To improve security and privacy, we are moving our web pages and services from HTTP to HTTPS.
To give users of web services time to transition to HTTPS, we will support separate HTTP and HTTPS services until the end of 2017.
From January 2018 most HTTP traffic will be automatically redirected to HTTPS. [more...]
View this page in https
PROSITE documentation PDOC00406 [for PROSITE entry PS51278]

Glutamine amidotransferase type 2 domain profile





Description

A large group of biosynthetic enzymes are able to catalyze the removal of the ammonia group from glutamine and then to transfer this group to a substrate to form a new carbon-nitrogen group. This catalytic activity is known as glutamine amidotransferase (GATase) (EC 2.4.2.-) [1]. The GATase domain exists either as a separate polypeptidic subunit or as part of a larger polypeptide fused in different ways to a synthase domain. On the basis of sequence similarities two classes of GATase domains have been identified [2,3]: class-I (also known as trpG-type or triad) (see <PDOC00405>) and class-II (also known as purF-type or Ntn). Class-II (or type 2) GATase domains have been found in the following enzymes:

  • Amido phosphoribosyltransferase (glutamine phosphoribosylpyrophosphate amidotransferase) (EC 2.4.2.14). An enzyme which catalyzes the first step in purine biosynthesis, the transfer of the ammonia group of glutamine to PRPP to form 5-phosphoribosylamine (gene purF in bacteria, ADE4 in yeast).
  • Glucosamine--fructose-6-phosphate aminotransferase (EC 2.6.1.16). This enzyme catalyzes a key reaction in amino sugar synthesis, the formation of glucosamine 6-phosphate from fructose 6-phosphate and glutamine (gene glmS in Escherichia coli, nodM in Rhizobium, GFA1 in yeast).
  • Asparagine synthetase (glutamine-hydrolyzing) (EC 6.3.5.4). This enzyme is responsible for the synthesis of asparagine from aspartate and glutamine.
  • Glutamate synthase (gltS), an enzyme which participates in the ammonia assimilation process by catalyzing the formation of glutamate from glutamine and 2-oxoglutarate. Glutamate synthase is a multicomponent iron-sulfur flavoprotein and three types occur which use a different electron donor: NADPH-dependent gltS (large chain) (EC 1.4.1.13), ferredoxin-dependent gltS (EC 1.4.7.1) and NADH-dependent gltS (EC 1.4.1.14) [4].

The active site is formed by a cysteine present at the N-terminal extremity of the mature form of all these enzymes [5,6,7,8]. Two other conserved residues, Asn and Gly, form an oxyanion hole for stabilization of the formed tetrahedral intermediate. An insert of ~120 residues can occur between the conserved regions [4]. In some class-II GATases (for example in Bacillus subtilis or chicken amido phosphoribosyltransferase) the enzyme is synthesized with a short propeptide which is cleaved off post-translationally by a proposed autocatalytic mechanism. Nuclear-encoded Fd-dependent gltS have a longer propeptide which may contain a chloroplast-targeting peptide in additon to the propeptide that is excised on enzyme activation [4].

The 3-D structure of the GATase type 2 domain forms a four layer α/β/β/α architecture (see <PDB:1LM1>) which consists of a fold similar to the N-terminal nucleophile (Ntn) hydrolases. These have the capacity for nucleophilic attack and the possibility of autocatalytic processing. The N-terminal position and the folding of the catalytic Cys differ strongly from the Cys-His-Glu triad which forms the active site of GATases of type 1 (see <PDOC00405>).

The profile we developed covers the entire GATase type 2 domain.

Last update:

November 2006 / Pattern removed, profile added and text revised.

Technical section

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

GATASE_TYPE_2, PS51278; Glutamine amidotransferase type 2 domain profile  (MATRIX)


References

1AuthorsBuchanan J.M.
TitleThe amidotransferases.
SourceAdv. Enzymol. Relat. Areas Mol. Biol. 39:91-183(1973).
PubMed ID4355768

2AuthorsWeng M.L., Zalkin H.
TitleStructural role for a conserved region in the CTP synthetase glutamine amide transfer domain.
SourceJ. Bacteriol. 169:3023-3028(1987).
PubMed ID3298209

3AuthorsNyunoya H., Lusty C.J.
TitleSequence of the small subunit of yeast carbamyl phosphate synthetase and identification of its catalytic domain.
SourceJ. Biol. Chem. 259:9790-9798(1984).
PubMed ID6086650

4AuthorsVanoni M.A., Curti B.
TitleGlutamate synthase: a complex iron-sulfur flavoprotein.
SourceCell. Mol. Life Sci. 55:617-638(1999).
PubMed ID10357231

5AuthorsVollmer S.J., Switzer R.L., Hermodson M.A., Bower S.G., Zalkin H.
TitleThe glutamine-utilizing site of Bacillus subtilis glutamine phosphoribosylpyrophosphate amidotransferase.
SourceJ. Biol. Chem. 258:10582-10585(1983).
PubMed ID6411716

6AuthorsVan Heeke G., Schuster S.M.
TitleThe N-terminal cysteine of human asparagine synthetase is essential for glutamine-dependent activity.
SourceJ. Biol. Chem. 264:19475-19477(1989).
PubMed ID2573597

7AuthorsMassiere F., Badet-Denisot M.A.
TitleThe mechanism of glutamine-dependent amidotransferases.
SourceCell. Mol. Life Sci. 54:205-222(1998).
PubMed ID9575335

8Authorsvan den Heuvel R.H.H., Curti B., Vanoni M.A., Mattevi A.
TitleGlutamate synthase: a fascinating pathway from L-glutamine to L-glutamate.
SourceCell. Mol. Life Sci. 61:669-681(2004).
PubMed ID15052410
DOI10.1007/s00018-003-3316-0



PROSITE is copyright. It is produced by the SIB Swiss Institute Bioinformatics. There are no restrictions on its use by non-profit institutions as long as its content is in no way modified. Usage by and for commercial entities requires a license agreement. For information about the licensing scheme send an email to
Prosite License or see: prosite_license.html.

Miscellaneous

View entry in original PROSITE document format
View entry in raw text format (no links)