Q6MUA3 · PYRG_MYCMS

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 site54L-glutamine (UniProtKB | ChEBI)
Binding site71ATP (UniProtKB | ChEBI)
Binding site71Mg2+ (UniProtKB | ChEBI)
Binding site141Mg2+ (UniProtKB | ChEBI)
Binding site148-150CTP (UniProtKB | ChEBI); allosteric inhibitor
Binding site188-193CTP (UniProtKB | ChEBI); allosteric inhibitor
Binding site188-193UTP (UniProtKB | ChEBI)
Binding site224CTP (UniProtKB | ChEBI); allosteric inhibitor
Binding site224UTP (UniProtKB | ChEBI)
Binding site354L-glutamine (UniProtKB | ChEBI)
Active site381Nucleophile; for glutamine hydrolysis
Binding site382-385L-glutamine (UniProtKB | ChEBI)
Binding site405L-glutamine (UniProtKB | ChEBI)
Binding site461L-glutamine (UniProtKB | ChEBI)
Active site506
Active site508

GO annotations

AspectTerm
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

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
    • Synonyms
      ctrA
    • Ordered locus names
      MSC_0134

Organism names

Accessions

  • Primary accession
    Q6MUA3

Proteomes

PTM/Processing

Features

Showing features for chain.

TypeIDPosition(s)Description
ChainPRO_00002661581-532CTP synthase

Interaction

Subunit

Homotetramer.

Protein-protein interaction databases

Structure

Family & Domains

Features

Showing features for region, domain.

TypeIDPosition(s)Description
Region1-267Amidoligase domain
Domain292-532Glutamine amidotransferase type-1

Sequence similarities

Belongs to the CTP synthase family.

Keywords

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    532
  • Mass (Da)
    59,608
  • Last updated
    2004-07-05 v1
  • Checksum
    18BB7FA1C045EE11
MAKFIFVTGGVVSGLGKGITASSIGALLKASGLKVFMQKFDPYLNVDPGTMSPYQHGEVFVTKDGGETDLDLGHYERFIDEELTKLSSTTSGKIYLSVIQGERKGVNSGKTIQVVPHITDAIKQKVYQAAKQSQADVIISEIGGTVGDIESQPFIEAIRQIRLEQGKENVMFVHVVLLLWLAASKEYKTKPIQNSVKAMASLGIQPDVIVCRSDSSSPKDIKEKISLFCNVPITNIIDAIDQDSIYRVPLALAKQNLQDIIIEQLQLKAKNIDLSLWKQFNKKIDSSTEEIEISFVGKYIELQDAYLSVLESLKIAGWEFNKKIKIRWVQADKLDESNYKEVLKNSQGILVPGGFGKRGIEGMMLASRYARENDIPYLGICLGMQIATISIARDLLNWSDADSTEFNKNTTHPIFDYIKGIDRDNIGGTLRLGTMVTKLEKNSLVSKLYNSDIALERHRHRYEFNNEYKKDLESVGLRFSGIYEEKNIVEVVEMPSLKFFVASQFHPEFTSRPNKPTPLFKGFIKAIVENNK

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
BX293980
EMBL· GenBank· DDBJ
CAE76781.1
EMBL· GenBank· DDBJ
Genomic DNA

Genome annotation databases

Similar Proteins

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