G2II36 · G2II36_SPHSK

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 site13CTP (UniProtKB | ChEBI); allosteric inhibitor
Binding site13UTP (UniProtKB | ChEBI)
Binding site14-19ATP (UniProtKB | ChEBI)
Binding site54L-glutamine (UniProtKB | ChEBI)
Binding site71ATP (UniProtKB | ChEBI)
Binding site71Mg2+ (UniProtKB | ChEBI)
Binding site139Mg2+ (UniProtKB | ChEBI)
Binding site146-148CTP (UniProtKB | ChEBI); allosteric inhibitor
Binding site186-191CTP (UniProtKB | ChEBI); allosteric inhibitor
Binding site186-191UTP (UniProtKB | ChEBI)
Binding site222CTP (UniProtKB | ChEBI); allosteric inhibitor
Binding site222UTP (UniProtKB | ChEBI)
Binding site240ATP (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 site471L-glutamine (UniProtKB | ChEBI)
Active site516
Active site518

GO annotations

AspectTerm
Molecular FunctionATP binding
Molecular FunctionCTP synthase activity
Molecular Functionglutaminase activity
Molecular Functionmetal ion binding
Biological Process'de novo' CTP biosynthetic process
Biological Processglutamine metabolic 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
    • ORF names
      SLG_22840

Organism names

Accessions

  • Primary accession
    G2II36

Proteomes

Interaction

Subunit

Homotetramer.

Protein-protein interaction databases

Family & Domains

Features

Showing features for region, domain.

TypeIDPosition(s)Description
Region1-265Amidoligase domain
Domain3-264CTP synthase N-terminal
Domain302-535Glutamine amidotransferase

Sequence similarities

Belongs to the CTP synthase family.

Keywords

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    544
  • Mass (Da)
    59,566
  • Last updated
    2011-11-16 v1
  • Checksum
    09BE31ACE1D3C71F
MARFIFITGGVVSSLGKGLMAASLAALLQARGFKVRTRKFDPYLNVDPGTMSPYQHGEVYVTDDGAETDLDLGHYERFTGVVSRQADNVTQGRIYQTIIQKERRGDYLGATVQVIPHVTDEIKAFALAETGDVDFVLCEIGGTVGDIESLPFMEAIRQLHNELGPKQSIFVHVTLVPYIAAAGELKTKPTQHSVRELTSLGIQPHILLCRTEHPLPDSERAKIALFCNVPTDAVIPALDASSIYAVPAQYHAEGLDAAVLRAFDIEGAPAPDMARWIDIMDRQQNPEGEVTIGVVGKYVGLPDAYKSLHEALVHGGLANRVKVRIQWLDAELFEEEESDIAARLEPMHGILVPGGFGVRGSEGKIASVRFARERNVPFFGICLGMQMACIESARNTAGIAGASTTEFGPTDEPVVGLITEWMSKEGLQKRTEQTDLGGTMRLGAYPAKLAGNSVVASIYEAEEISERHRHRYEVNARYREPLEKGGLIFSGMSPDGQLPEIVERPDHSWFIGVQFHPELKSKPFDPHPLFASFIAAALKQSRLV

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
AP012222
EMBL· GenBank· DDBJ
BAK66959.1
EMBL· GenBank· DDBJ
Genomic DNA

Genome annotation databases

Similar Proteins

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