Q939R0 · PYRG_FIBSS

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.

TypeIDPosition(s)Description
Binding site24CTP (UniProtKB | ChEBI); allosteric inhibitor
Binding site24UTP (UniProtKB | ChEBI)
Binding site25-30ATP (UniProtKB | ChEBI)
Binding site65L-glutamine (UniProtKB | ChEBI)
Binding site82ATP (UniProtKB | ChEBI)
Binding site82Mg2+ (UniProtKB | ChEBI)
Binding site151Mg2+ (UniProtKB | ChEBI)
Binding site158-160CTP (UniProtKB | ChEBI); allosteric inhibitor
Binding site198-203CTP (UniProtKB | ChEBI); allosteric inhibitor
Binding site198-203UTP (UniProtKB | ChEBI)
Binding site234CTP (UniProtKB | ChEBI); allosteric inhibitor
Binding site234UTP (UniProtKB | ChEBI)
Binding site250-252ATP (UniProtKB | ChEBI)
Binding site363L-glutamine (UniProtKB | ChEBI)
Active site390Nucleophile; for glutamine hydrolysis
Binding site391-394L-glutamine (UniProtKB | ChEBI)
Binding site414L-glutamine (UniProtKB | ChEBI)
Binding site471L-glutamine (UniProtKB | ChEBI)
Active site518
Active site520

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 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
      Fisuc_1822, FSU_2325

Organism names

Accessions

  • Primary accession
    Q939R0
  • Secondary accessions
    • C9RS78
    • D9S4K4

Proteomes

Subcellular Location

PTM/Processing

Features

Showing features for chain.

TypeIDPosition(s)Description
ChainPRO_00001381861-563CTP synthase

Interaction

Subunit

Homotetramer.

Protein-protein interaction databases

Structure

Family & Domains

Features

Showing features for region, domain.

TypeIDPosition(s)Description
Region1-278Amidoligase domain
Domain303-545Glutamine amidotransferase type-1
Region542-563Disordered

Sequence similarities

Belongs to the CTP synthase family.

Keywords

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    563
  • Mass (Da)
    62,460
  • Last updated
    2010-01-19 v2
  • Checksum
    768352B39EE391D6
MAKATAKNSAKQPKYIFITGGVVSSLGKGITSASLALLLKSRGYKVFMQKLDPYLNVDPGTMSPYQHGEVFVTDDGYETDLDLGHYERFAGVQCSKASSYTSGRIYSSVLSKERAGHYLGGTVQVIPHITNEIKDAFRSAAESGADIILCEIGGVAGDIESLPFLEAARQFRFEVGVENTCFIHLTLVPYLKAAGELKTKPSQHSVAELRNIGIFPDILVCRTEMHIPQEHLDKLALFCNVKPECVIEEKDVKDSVYAVPRELSKQELDLRVLEQLHLSVHPIVHSEWDSLVKKATQPKYECTIALVGKYIAIRDAYKSVHEALQHAGMANNAKVNVECIEAEELEKNPKLIKKADGILIPGGFGSRGVNGKCAAIRYARENKVPLLGICLGMQCCVIEFARDVLGWKDANSTEFDENTTHPVIDLMDEQKNVTEKGGTMRLGAYPCKLAKDSNAAKLYKSEKISERHRHRYEFNYNSEFRKELEKAGLKIAGTSPDGKLVEMVELKNHPYFEACQFHPEFKSRPTDPHPLFTGLVKAALEQKKANGKKPTAPSEKTKKTKTK

Features

Showing features for sequence conflict.

TypeIDPosition(s)Description
Sequence conflict395-397in Ref. 3; AAK13023
Sequence conflict403in Ref. 3; AAK13023
Sequence conflict407-409in Ref. 3; AAK13023
Sequence conflict421-428in Ref. 3; AAK13023
Sequence conflict432-435in Ref. 3; AAK13023
Sequence conflict444in Ref. 3; AAK13023
Sequence conflict457-458in Ref. 3; AAK13023
Sequence conflict461in Ref. 3; AAK13023
Sequence conflict465in Ref. 3; AAK13023

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
CP001792
EMBL· GenBank· DDBJ
ACX75414.1
EMBL· GenBank· DDBJ
Genomic DNA
CP002158
EMBL· GenBank· DDBJ
ADL27373.1
EMBL· GenBank· DDBJ
Genomic DNA
AY017383
EMBL· GenBank· DDBJ
AAK13023.1
EMBL· GenBank· DDBJ
Genomic DNA

Genome annotation databases

Similar Proteins

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