B3QRL0 · PYRG_CHLP8

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 site18CTP (UniProtKB | ChEBI); allosteric inhibitor
Binding site18UTP (UniProtKB | ChEBI)
Binding site19-24ATP (UniProtKB | ChEBI)
Binding site59L-glutamine (UniProtKB | ChEBI)
Binding site76ATP (UniProtKB | ChEBI)
Binding site76Mg2+ (UniProtKB | ChEBI)
Binding site146Mg2+ (UniProtKB | ChEBI)
Binding site153-155CTP (UniProtKB | ChEBI); allosteric inhibitor
Binding site193-198CTP (UniProtKB | ChEBI); allosteric inhibitor
Binding site193-198UTP (UniProtKB | ChEBI)
Binding site229CTP (UniProtKB | ChEBI); allosteric inhibitor
Binding site229UTP (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 site516
Active site518

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
      Cpar_0097

Organism names

Accessions

  • Primary accession
    B3QRL0

Proteomes

Subcellular Location

PTM/Processing

Features

Showing features for chain.

TypeIDPosition(s)Description
ChainPRO_10001394151-565CTP synthase

Interaction

Subunit

Homotetramer.

Protein-protein interaction databases

Structure

Family & Domains

Features

Showing features for region, domain.

TypeIDPosition(s)Description
Region1-272Amidoligase domain
Domain299-543Glutamine amidotransferase type-1

Sequence similarities

Belongs to the CTP synthase family.

Keywords

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    565
  • Mass (Da)
    63,735
  • Last updated
    2008-09-02 v1
  • Checksum
    E699FFAB04D3065B
MARPKNVKHIFVTGGVISSLGKGILSASLGMLLKSRGLRVAIQKYDPYINVDPGTMSPYQHGEVYVTDDGAETDLDLGHYERFLDEPTSQASNLTMGRVYKSVIDKERRGEYLGGTVQVVPHVIDEIKEKMNDLAKNGSLDVLITEIGGTIGDIESLPFLEAMRQLKLELGDRNVLNIHLTFVPYIKAASELKTKPTQHSVKMLLETGIQPDILVCRSEKPLSREIKNKVGHFCNVHEQDVIGLNDCETIYAVPLMLLREQLDLRVMKKLGLKKFREPNLEHWKRFCEKVTNPKDGEITIGVCGKYTEYPDAYKSIIEAFIHAGASNDVKVSVKMLRAEDAEDSSFNMNKAFEGVSGLLVAPGFGDRGIEGKVQFVQYARENNIPFFGICLGMQCASIEFARNVCDLPDANSTEFNKRARFPVIDLMEQQKKVKEKGGTMRLGSYPCILKEGSKVHEVYGKFLINERHRHRYEFNNQFRKLFEEKGMIFSGTSPNGELVEIIELKEHRWFVAVQFHPELKSRVQKVHPLFDGFVQAAKEFAMGKRQLTLEDELPRLSSEEMEGAG

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
CP001099
EMBL· GenBank· DDBJ
ACF10525.1
EMBL· GenBank· DDBJ
Genomic DNA

Genome annotation databases

Similar Proteins

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