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Annotation rule MF_01249
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General rule information [?]

Accession MF_01249
Dates 26-APR-2004 (Created)
19-NOV-2019 (Last updated, Version 24)
Name HPr_kinase
Scope
Bacteria
Templates O34483 (HPRK_BACSU); Q9RE09 (HPRK_LACCA); P75548 (HPRK_MYCPN); Q9S1H5 (HPRK_STAXY); Q9WXK7 (HPRK_STREI); Q9ZA98 (HPRK_STRSL): [Recover all]

Propagated annotation [?]


Identifier, protein and gene names [?]

Identifier
HPRK
Protein name
RecName: Full=HPr kinase/phosphorylase;
Short=HPrK/P;
EC 2.7.11.-;
EC 2.7.4.-;
AltName: Full=HPr(Ser) kinase/phosphorylase;
Gene name
hprK

Comments [?]

case <OC:Bacillaceae>
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. Also phosphorylates/dephosphorylates the HPr-like catabolite repression protein crh on a specific serine residue. Therefore, by controlling the phosphorylation state of HPr and crh, 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.
end case
case <OC:Firmicutes> and not <OC:Bacillaceae>
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.
end case
case not <OC:Firmicutes>
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).
end case
Catalytic activity RHEA:46600: [HPr protein]-L-serine + ATP = [HPr protein]-O-phospho-L-serine + ADP + H(+)
RHEA:46604: [HPr protein]-O-phospho-L-serine + H(+) + phosphate = [HPr protein]-L-serine + diphosphate
Cofactor Mg(2+)
Subunit Homohexamer.
Domain The Walker A ATP-binding motif also binds Pi and PPi.
Miscellaneous Both phosphorylation and phosphorolysis are carried out by the same active site and suggest a common mechanism for both reactions.
Similarity Belongs to the HPrK/P family.

Keywords [?]

case <OC:Firmicutes>
end case

Gene Ontology [?]

GO:0000287; Molecular function: magnesium ion binding.
GO:0004712; Molecular function: protein serine/threonine/tyrosine kinase activity.
GO:0005524; Molecular function: ATP binding.
GO:0006109; Biological process: regulation of carbohydrate metabolic process.

Cross-references [?]

Pfam PF07475; Hpr_kinase_C; 1;
PF02603; Hpr_kinase_N; 1;
TIGRFAMs TIGR00679; Hpr-ser; 1;

Features [?]

From: HPRK_LACCA (Q9RE09)
Key     From     To       Description   Tag   Condition   FTGroup
NP_BIND     155     162       ATP     G-x-[SA]-G-x-G-K-S  
ACT_SITE     140     140             H  
ACT_SITE     161     161             K  
ACT_SITE     179     179       Proton acceptor; for phosphorylation activity. Proton donor; for dephosphorylation activity     D  
ACT_SITE     245     245             R  
METAL     162     162       Magnesium     S  
METAL     204     204       Magnesium     E  
REGION     203     212       Important for the catalytic mechanism of both phosphorylation and dephosphorylation        
REGION     266     271       Important for the catalytic mechanism of dephosphorylation        

Additional information [?]

Size range 301-342 amino acids
Related rules None
Fusion None
Comments This enzyme was originally called HPr kinase/phosphatase, but P-Ser-HPr dephosphorylation was recently found to follow a quite unique mechanism, in which Pi instead of H(2)O is used for the nucleophilic attack on the phosphoryl group. P-Ser-HPr dephosphorylation is therefore not a phosphohydrolysis but a phosphophosphorolysis reaction, and the bifunctional enzyme was dubbed HPr kinase/phosphorylase. The regulatory role(s) of HPrK/P in bacterial physiology may be quite diverse. In low GC Gram-positive bacteria, HPr kinase/phosphorylase plays a major role in the regulation of carbon metabolism as it is a bifunctional sensor enzyme for CCR, PTS-catalyzed sugar transport and inducer exclusion. But HPRK/P must carry out different regulatory functions in Gram-negative bacteria, as these bacteria are devoid of ccpA protein, and a functional PTS also seems to be absent. The gene organization in many hprK-containing Gram-negative bacteria strongly suggest that HPrK/P regulates either a two-component sensory system implicated in cell adhesion/virology or rpoN-like sigma-factors. In Fusobacterium nucleatum, this protein is composed of two complete HPrK/P domains fused in tandem.