Q5HQW8 · HPRK_STAEQ

Function

function

Catalyzes the ATP- as well as the pyrophosphate-dependent phosphorylation of a specific serine residue in HPr, a phosphocarrier protein of the phosphoenolpyruvate-dependent sugar phosphotransferase system (PTS). HprK/P also catalyzes the pyrophosphate-producing, inorganic phosphate-dependent dephosphorylation (phosphorolysis) of seryl-phosphorylated HPr (P-Ser-HPr). The two antagonistic activities of HprK/P are regulated by several intracellular metabolites, which change their concentration in response to the absence or presence of rapidly metabolisable carbon sources (glucose, fructose, etc.) in the growth medium. Therefore, by controlling the phosphorylation state of HPr, HPrK/P is a sensor enzyme that plays a major role in the regulation of carbon metabolism and sugar transport: it mediates carbon catabolite repression (CCR), and regulates PTS-catalyzed carbohydrate uptake and inducer exclusion.

Miscellaneous

Both phosphorylation and phosphorolysis are carried out by the same active site and suggest a common mechanism for both reactions.

Catalytic activity

Cofactor

Mg2+ (UniProtKB | Rhea| CHEBI:18420 )

Features

Showing features for active site, binding site.

TypeIDPosition(s)Description
Active site136
Binding site151-158ATP (UniProtKB | ChEBI)
Active site157
Binding site158Mg2+ (UniProtKB | ChEBI)
Active site175Proton acceptor; for phosphorylation activity. Proton donor; for dephosphorylation activity
Binding site200Mg2+ (UniProtKB | ChEBI)
Active site241

GO annotations

AspectTerm
Molecular FunctionATP binding
Molecular Functionmagnesium ion binding
Molecular Functionphosphorelay sensor kinase activity
Molecular Functionprotein serine/threonine kinase activity
Molecular Functionprotein serine/threonine/tyrosine kinase activity
Biological Processregulation of carbohydrate metabolic process

Keywords

Enzyme and pathway databases

Names & Taxonomy

Protein names

  • Recommended name
    HPr kinase/phosphorylase
  • EC number
  • Short names
    HPrK/P
  • Alternative names
    • HPr(Ser) kinase/phosphorylase

Gene names

    • Name
      hprK
    • Ordered locus names
      SERP0428

Organism names

Accessions

  • Primary accession
    Q5HQW8

Proteomes

PTM/Processing

Features

Showing features for chain.

TypeIDPosition(s)Description
ChainPRO_00000589881-310HPr kinase/phosphorylase

Interaction

Subunit

Homohexamer.

Protein-protein interaction databases

Structure

Family & Domains

Features

Showing features for region.

TypeIDPosition(s)Description
Region199-208Important for the catalytic mechanism of both phosphorylation and dephosphorylation
Region262-267Important for the catalytic mechanism of dephosphorylation

Domain

The Walker A ATP-binding motif also binds Pi and PPi.

Sequence similarities

Belongs to the HPrK/P family.

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    310
  • Mass (Da)
    34,696
  • Last updated
    2005-02-15 v1
  • Checksum
    1529D552263AF0EE
MLTTDRLVNTLNLELLTGEEGLDRPIKNTDISRPGLEMAGYFSHYASDRIQLLGTTELSFYNLLPDEEKKGRMRKLCRPETPAIIVTRGLEPPEELIQASQETHTPIIVAKDATTSLMSRLTTFLEHELAKTTSLHGVLVDVYGVGVLITGDSGIGKSETALELVKRGHRLVADDNVEIKEITKDELVGKPPKLIEHLLEIRGLGIINVMTLFGAGSILTEKQIRLNINLENWNKNKLYDRVGLNEETLKILDTEITKKTIPVRPGRNVAVIIEVAAMNYRLNIMGINTAVEFNERLNEEIVRNSHKSEE

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
CP000029
EMBL· GenBank· DDBJ
AAW53842.1
EMBL· GenBank· DDBJ
Genomic DNA

Genome annotation databases

Similar Proteins

Disclaimer

Any medical or genetic information present in this entry is provided for research, educational and informational purposes only. It is not in any way intended to be used as a substitute for professional medical advice, diagnosis, treatment or care. Our staff consists of biologists and biochemists that are not trained to give medical advice.
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