Q8EBQ9 · PYRG_SHEON

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.

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.

Type
IDPosition(s)Description
Binding site14CTP (UniProtKB | ChEBI); allosteric inhibitor
Binding site14UTP (UniProtKB | ChEBI)
Binding site15-20ATP (UniProtKB | ChEBI)
Binding site72ATP (UniProtKB | ChEBI)
Binding site72Mg2+ (UniProtKB | ChEBI)
Binding site140Mg2+ (UniProtKB | ChEBI)
Binding site147-149CTP (UniProtKB | ChEBI); allosteric inhibitor
Binding site187-192CTP (UniProtKB | ChEBI); allosteric inhibitor
Binding site187-192UTP (UniProtKB | ChEBI)
Binding site223CTP (UniProtKB | ChEBI); allosteric inhibitor
Binding site223UTP (UniProtKB | ChEBI)
Binding site239-241ATP (UniProtKB | ChEBI)
Binding site352L-glutamine (UniProtKB | ChEBI)
Active site379Nucleophile; for glutamine hydrolysis
Binding site380-383L-glutamine (UniProtKB | ChEBI)
Binding site403L-glutamine (UniProtKB | ChEBI)
Binding site470L-glutamine (UniProtKB | ChEBI)
Active site515
Active site517

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

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
      SO_3441

Organism names

Accessions

  • Primary accession
    Q8EBQ9

Proteomes

Subcellular Location

PTM/Processing

Features

Showing features for chain.

TypeIDPosition(s)Description
ChainPRO_00002662141-546CTP synthase

Proteomic databases

Interaction

Subunit

Homotetramer.

Protein-protein interaction databases

Structure

Family & Domains

Features

Showing features for region, domain.

Type
IDPosition(s)Description
Region1-266Amidoligase domain
Domain291-542Glutamine amidotransferase type-1

Sequence similarities

Belongs to the CTP synthase family.

Keywords

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    546
  • Mass (Da)
    60,149
  • Last updated
    2003-03-01 v1
  • Checksum
    4079A1DB93CF39E7
MTTRYIFVTGGVVSSLGKGIAAASLAAILEARGLNVTIMKLDPYINVDPGTMSPTQHGEVFVTEDGAETDLDLGHYERFIRTKMNRRNNFTTGRIYEEVLRKERRGDYLGATIQVIPHITNAIKEKVLAGGEGHDVAIVEIGGTVGDIESLPFLESIRQLGVELGRDRTLFMHLTLVPFLGAAGEVKTKPTQHSVKELRSIGIAPDVLICRGDRAIPANERAKISLFCNVEERAVISLKDVDSIYKIPALLRSQGLDELVVKRFSLTCREADLSEWENVIYQEANPNGEVVIGMVGKYIELPDAYKSVNEALKHAGLKNRVSVTIKYIDSQTVEAKGDEVLQGLDGILVPGGFGERGVEGKILAAKFARENNLPYFGICLGMQVALIEFARNVAGMADAHSTEFNKATPFPVVGLITEWVDEEGNVEQRHEASDLGGTMRLGAQLCHLLEGSKAAQAYKGNSCVERHRHRYEVNNKYKERLEQAGLVFSGLSSDRKLVEMIELKDHPWFVAGQFHPEFTSTPRDGHPLFEGFVAAASAHQKRDLKK

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
AE014299
EMBL· GenBank· DDBJ
AAN56438.1
EMBL· GenBank· DDBJ
Genomic DNA

Genome annotation databases

Similar Proteins

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