P65924 · PYRG_STAAW

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.

Type
IDPosition(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 site240-242ATP (UniProtKB | ChEBI)
Binding site355L-glutamine (UniProtKB | ChEBI)
Active site382Nucleophile; for glutamine hydrolysis
Binding site383-386L-glutamine (UniProtKB | ChEBI)
Binding site406L-glutamine (UniProtKB | ChEBI)
Binding site463L-glutamine (UniProtKB | ChEBI)
Active site508
Active site510

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 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
      MW2051

Organism names

Accessions

  • Primary accession
    P65924
  • Secondary accessions
    • Q99SD1

Proteomes

Subcellular Location

PTM/Processing

Features

Showing features for chain.

TypeIDPosition(s)Description
ChainPRO_00001382271-536CTP synthase

Interaction

Subunit

Homotetramer.

Structure

Family & Domains

Features

Showing features for region, domain.

Type
IDPosition(s)Description
Region1-267Amidoligase domain
Domain293-535Glutamine amidotransferase type-1

Sequence similarities

Belongs to the CTP synthase family.

Keywords

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    536
  • Mass (Da)
    59,992
  • Last updated
    2004-10-11 v1
  • MD5 Checksum
    4CE5C1350842AB8DDF2480712619A0F3
MTKFIFVTGGVVSSLGKGITASSLGRLLKDRGLNVTIQKFDPYLNVDPGTMSPYQHGEVFVTDDGAETDLDLGHYERFIDINLNKFSNVTAGKVYSHVLKKERRGDYLGGTVQVIPHITNEIKERLLLAGESTNADVVITEIGGTTGDIESLPFIEAIRQIRSDLGRENVMYVHCTLLPYIKAAGEMKTKPTQHSVKELRGLGIQPDLIVVRTEYEMTQDLKDKIALFCDINKESVIECRDADSLYEIPLQLSQQNMDDIVIKRLQLNAKYETQLDEWKQLLDIVNNLDGKITIGLVGKYVSLQDAYLSVVESLKHAGYPFAKDIDIRWIDSSEVTDENAAEYLADVDGILVPGGFGFRASEGKISAIKYARENNVPFFGICLGMQLATVEFSRNVLGLEGAHSAELDPATPYPIIDLLPEQKDIEDLGGTLRLGLYPCSIKEGTLAQDVYGKAEIEERHRHRYEFNNDYREQLEANGMVISGTSPDGRLVEMVEIPTNDFFIACQFHPEFLSRPNRPHPIFKSFIEASLKYQQNK

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
BA000033
EMBL· GenBank· DDBJ
BAB95916.1
EMBL· GenBank· DDBJ
Genomic DNA

Genome annotation databases

Similar Proteins

Disclaimer

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