B3Q0M2 · PYRG_RHIE6

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 site13CTP (UniProtKB | ChEBI); allosteric inhibitor
Binding site13UTP (UniProtKB | ChEBI)
Binding site14-19ATP (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 site353L-glutamine (UniProtKB | ChEBI)
Active site380Nucleophile; for glutamine hydrolysis
Binding site381-384L-glutamine (UniProtKB | ChEBI)
Binding site404L-glutamine (UniProtKB | ChEBI)
Binding site469L-glutamine (UniProtKB | ChEBI)
Active site514
Active site516

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

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
      RHECIAT_CH0002271

Organism names

  • Taxonomic identifier
  • Strain
    • CIAT 652
  • Taxonomic lineage
    Bacteria > Pseudomonadota > Alphaproteobacteria > Hyphomicrobiales > Rhizobiaceae > Rhizobium/Agrobacterium group > Rhizobium

Accessions

  • Primary accession
    B3Q0M2

Proteomes

PTM/Processing

Features

Showing features for chain.

TypeIDPosition(s)Description
ChainPRO_10001395441-542CTP synthase

Interaction

Subunit

Homotetramer.

Structure

Family & Domains

Features

Showing features for region, domain.

TypeIDPosition(s)Description
Region1-265Amidoligase domain
Domain291-541Glutamine amidotransferase type-1

Sequence similarities

Belongs to the CTP synthase family.

Keywords

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    542
  • Mass (Da)
    59,968
  • Last updated
    2008-09-02 v1
  • Checksum
    0FAB6B710232E40E
MARYVFITGGVVSSLGKGIAAAALGALLQARGYRVRLRKLDPYLNVDPGTMSPTQHGEVFVTDDGAETDLDLGHYERFTGRSATKTDNITTGRIYKNIIDKERRGDYLGATVQVIPHVTNEIKDFVTEGNKDYDFVICEIGGTVGDIEAMPFMEAIRQLGNDLPRGTAVYVHLTLMPYIPAAGELKTKPTQHSVKELQALGIHPDILLVRADREIPEAERRKLSLFCNVRPSAVIQALDVANIYDVPMAYHKEGLDDEVLAAFGIEPAPKPRLDQWEEVCNRIRTPEGEVTIAIVGKYTGLKDAYKSLIEALHHGGIANRVKVKLEWIESEVFEKEDPAPYLEKVHGILVPGGFGERGSEGKIHAARFARERKVPYFGICFGMQMAVIEAARNLADVPDASSTEFGPAKEPVVGLMTEWVKGNELQKRTAAGDLGGTMRLGAYKAALKKGTKISEIYGSTDISERHRHRYEVNIDYKDRLESCGLVFSGMSPDGVLPETIEYPDHPWFIGVQYHPELKSRPLDPHPLFASFIEAATEQSRLV

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
CP001074
EMBL· GenBank· DDBJ
ACE91226.1
EMBL· GenBank· DDBJ
Genomic DNA

Genome annotation databases

Similar Proteins

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