Q0SI74 · PYRG_RHOJR

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 site23CTP (UniProtKB | ChEBI); allosteric inhibitor
Binding site23UTP (UniProtKB | ChEBI)
Binding site24-29ATP (UniProtKB | ChEBI)
Binding site81ATP (UniProtKB | ChEBI)
Binding site81Mg2+ (UniProtKB | ChEBI)
Binding site155Mg2+ (UniProtKB | ChEBI)
Binding site162-164CTP (UniProtKB | ChEBI); allosteric inhibitor
Binding site202-207CTP (UniProtKB | ChEBI); allosteric inhibitor
Binding site202-207UTP (UniProtKB | ChEBI)
Binding site238CTP (UniProtKB | ChEBI); allosteric inhibitor
Binding site238UTP (UniProtKB | ChEBI)
Binding site369L-glutamine (UniProtKB | ChEBI)
Active site396Nucleophile; for glutamine hydrolysis
Binding site397-400L-glutamine (UniProtKB | ChEBI)
Binding site419L-glutamine (UniProtKB | ChEBI)
Binding site480L-glutamine (UniProtKB | ChEBI)
Active site527
Active site529

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
      RHA1_ro00931

Organism names

Accessions

  • Primary accession
    Q0SI74

Proteomes

Subcellular Location

PTM/Processing

Features

Showing features for chain.

TypeIDPosition(s)Description
ChainPRO_00002661961-591CTP synthase

Interaction

Subunit

Homotetramer.

Structure

Family & Domains

Features

Showing features for region, domain, compositional bias.

TypeIDPosition(s)Description
Region1-281Amidoligase domain
Domain306-554Glutamine amidotransferase type-1
Compositional bias568-584Basic and acidic residues
Region568-591Disordered

Sequence similarities

Belongs to the CTP synthase family.

Keywords

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    591
  • Mass (Da)
    64,082
  • Last updated
    2006-09-05 v1
  • Checksum
    9F8C596DDF639633
MPQSRTHSRTATKHIFVSGGVASSLGKGLTASSLGQLLTARGMRVTMQKLDPYLNVDPGTMNPFQHGEVFVTDDGAETDLDVGHYERFLDRDLSGQANVTTGQVYSTVIAKERRGEYLGDTVQVIPHITDEIKSRILAMSGPDLQGHQPDVVITEIGGTVGDIESQPFLEAARQVRHDVGRDNVFFLHVSLVPYLAPSGELKTKPTQHSVAALRNIGIQPDALILRCDREVPPALKNKIALMCDVDVDGCISTPDAPSIYDIPKVLHSEGLDAYVVRQLGLPFRDVDWTVWGNLLERVHQPRETVRIALVGKYVDLPDAYLSVTEALRAGGFANRSKVEISWVPSDACETEAGAQAALGDVDGVLIPGGFGIRGIEGKLGAIRYARHRKIPLLGLCLGLQCVVIEAARSVGLDDANSAEFEPETTHPVISTMADQEDVIAGEADLGGTMRLGAYPAVLTKGSVVARAYGSEEVSERHRHRYEVNNAYRDRIAKSGLRFSGTSPDGHLVEFVEYPADQHPFFVATQAHPELKSRPTRPHPLFAAFVDAALKHKLEERLPVDVHGEERAAVATDDELADSADRDEVASVDSAG

Features

Showing features for compositional bias.

TypeIDPosition(s)Description
Compositional bias568-584Basic and acidic residues

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
CP000431
EMBL· GenBank· DDBJ
ABG92762.1
EMBL· GenBank· DDBJ
Genomic DNA

Genome annotation databases

Similar Proteins

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