A5HY28 · A5HY28_CLOBH

Function

function

Catalyzes the ATP-dependent amination of UTP to CTP with either L-glutamine or ammonia as the source of nitrogen. Regulates intracellular CTP levels through interactions with the four ribonucleotide triphosphates.

Miscellaneous

CTPSs have evolved a hybrid strategy for distinguishing between UTP and CTP. The overlapping regions of the product feedback inhibitory and substrate sites recognize a common feature in both compounds, the triphosphate moiety. To differentiate isosteric substrate and product pyrimidine rings, an additional pocket far from the expected kinase/ligase catalytic site, specifically recognizes the cytosine and ribose portions of the product inhibitor.

Caution

Lacks conserved residue(s) required for the propagation of feature annotation.

Catalytic activity

Activity regulation

Allosterically activated by GTP, when glutamine is the substrate; GTP has no effect on the reaction when ammonia is the substrate. The allosteric effector GTP functions by stabilizing the protein conformation that binds the tetrahedral intermediate(s) formed during glutamine hydrolysis. Inhibited by the product CTP, via allosteric rather than competitive inhibition.

Pathway

Pyrimidine metabolism; CTP biosynthesis via de novo pathway; CTP from UDP: step 2/2.

Features

Showing features for binding site, active site.

TypeIDPosition(s)Description
Binding site14CTP (UniProtKB | ChEBI); allosteric inhibitor
Binding site14UTP (UniProtKB | ChEBI)
Binding site15-20ATP (UniProtKB | ChEBI)
Binding site55L-glutamine (UniProtKB | ChEBI)
Binding site72ATP (UniProtKB | ChEBI)
Binding site72Mg2+ (UniProtKB | ChEBI)
Binding site142Mg2+ (UniProtKB | ChEBI)
Binding site149-151CTP (UniProtKB | ChEBI); allosteric inhibitor
Binding site189-194CTP (UniProtKB | ChEBI); allosteric inhibitor
Binding site189-194UTP (UniProtKB | ChEBI)
Binding site225CTP (UniProtKB | ChEBI); allosteric inhibitor
Binding site225UTP (UniProtKB | ChEBI)
Binding site243ATP (UniProtKB | ChEBI)
Binding site355L-glutamine (UniProtKB | ChEBI)
Active site382Nucleophile
Active site382Nucleophile; for glutamine hydrolysis
Binding site383-386L-glutamine (UniProtKB | ChEBI)
Binding site406L-glutamine (UniProtKB | ChEBI)
Binding site463L-glutamine (UniProtKB | ChEBI)
Active site508
Active site510

GO annotations

AspectTerm
Cellular Componentcytosol
Molecular FunctionATP binding
Molecular FunctionCTP synthase activity
Molecular Functionglutaminase activity
Molecular Functionidentical protein binding
Molecular Functionmetal ion binding
Biological Process'de novo' CTP biosynthetic process
Biological ProcessCTP biosynthetic process
Biological Processglutamine metabolic process
Biological Processpyrimidine nucleobase biosynthetic process

Keywords

Enzyme and pathway databases

Protein family/group databases

Names & Taxonomy

Protein names

  • Recommended name
    CTP synthase
  • EC number
  • Alternative names
    • Cytidine 5'-triphosphate synthase
    • Cytidine triphosphate synthetase
      (CTP synthetase
      ; CTPS
      )
    • UTP--ammonia ligase

Gene names

    • Name
      pyrG
    • Ordered locus names
      CBO0132

Organism names

Accessions

  • Primary accession
    A5HY28
  • Secondary accessions
    • A7G048

Proteomes

Subcellular Location

Interaction

Subunit

Homotetramer.

Family & Domains

Features

Showing features for region, domain.

TypeIDPosition(s)Description
Region1-268Amidoligase domain
Domain4-268CTP synthase N-terminal
Domain303-527Glutamine amidotransferase

Sequence similarities

Belongs to the CTP synthase family.

Keywords

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    533
  • Mass (Da)
    60,047
  • Last updated
    2007-06-26 v1
  • Checksum
    C54B15B9473B915A
MSTKYIFVTGGVVSSLGKGITAASLGRLLKNRGLKVSIQKFDPYINIDPGTMSPYQHGEVFVTEDGAETDLDLGHYERFIDENLSQNNNVTTGKIYWSVISKERKGDYLGATVQVIPHITTEIKSRVYRVAKEKEVDVVITEIGGTIGDIESLPFLESIRQIKYEVGRENVCFIHVTLLPFLGKAGELKTKPTQHSVKELRGIGIQPDIIVCRSEKQIPEELKGKIGLFCNVDKEDVIQNLDAENLYEVPLMLHKENLDTLVCKKLGLNYSKIDNTEWISMVNNAKNLSKNTTIALVGKYVELHDAYISIVEALNHGGYANDTKVNIKWINSEEVNENNFEQYLKDVDGILVPGGFGDRGIEGKIWAAKWARENKIPFLGICLGMQCAVIEFARNVLNYKGAHSAEIDPNTKYPVIDLMPEQKDIDNMGGTMRLGAYPCKLLKGTNSEKAYGQEIVYERHRHRYEFNNEYRSKLTEAGLILSGTSPDDRLVEIVEINNHPWYVAVQFHPELKSRPNKPHPLFKDFVKATLDKK

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
AM412317
EMBL· GenBank· DDBJ
CAL81687.1
EMBL· GenBank· DDBJ
Genomic DNA

Genome annotation databases

Similar Proteins

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