Information on EC 1.13.11.5 - homogentisate 1,2-dioxygenase

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The expected taxonomic range for this enzyme is: Eukaryota, Bacteria

EC NUMBER
COMMENTARY
1.13.11.5
-
RECOMMENDED NAME
GeneOntology No.
homogentisate 1,2-dioxygenase
REACTION
REACTION DIAGRAM
COMMENTARY
ORGANISM
UNIPROT ACCESSION NO.
LITERATURE
homogentisate + O2 = 4-maleylacetoacetate
show the reaction diagram
catalytic mechanism
-
homogentisate + O2 = 4-maleylacetoacetate
show the reaction diagram
reaction mechanism
Q88E47
homogentisate + O2 = 4-maleylacetoacetate
show the reaction diagram
reaction mechanism
Pseudomonas putida KT2400
-
-
homogentisate + O2 = 4-maleylacetoacetate
show the reaction diagram
-
-
-
-
REACTION TYPE
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
oxidation
-
-
-
-
redox reaction
-
-
-
-
reduction
-
-
-
-
PATHWAY
KEGG Link
MetaCyc Link
Metabolic pathways
-
Microbial metabolism in diverse environments
-
Styrene degradation
-
tyrosine degradation I
-
Tyrosine metabolism
-
SYSTEMATIC NAME
IUBMB Comments
homogentisate:oxygen 1,2-oxidoreductase (decyclizing)
Requires Fe2+.
SYNONYMS
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
EC 1.13.1.5
-
-
formerly
-
EC 1.99.2.5
-
-
formerly
-
HgD
B8YB76
-
HgD
Bos taurus Chinese red cattle
B8YB76
-
-
HgD
Q93099
-
HGDO
Q88E47
-
HGDO
Pseudomonas putida KT2400
Q88E47
-
-
HGO
-
-
-
-
HGOa
Vitis vinifera x Vitis riparia, Vitis vinifera x Vitis vinifera
-
-
HGOb
Vitis vinifera x Vitis riparia, Vitis vinifera x Vitis vinifera
-
-
HmgA
Pseudomonas putida KT 2440
-
-
-
homogentisate 1,2 dioxygenase
Q93099
-
homogentisate 1,2-dioxygenase
-
-
homogentisate 1,2-dioxygenase
-
-
homogentisate 1,2-dioxygenase
Vitis vinifera x Vitis riparia, Vitis vinifera x Vitis vinifera
-
-
homogentisate dioxygenase
-
-
-
-
homogentisate dioxygenase
Q9ZRA2
-
homogentisate dioxygenase
-
-
homogentisate dioxygenase
-
-
homogentisate dioxygenase
Q88E47
-
homogentisate dioxygenase
Pseudomonas putida KT2400
Q88E47
-
-
homogentisate oxidase
-
-
-
-
homogentisate oxygenase
-
-
-
-
homogentisate phytyl-transferase
-
involved in isoprenoid biosynthetic pathway
homogentisic acid 1,2-dioxygenase
-
-
homogentisic acid oxidase
-
-
-
-
homogentisic acid oxygenase
-
-
-
-
homogentisic oxygenase
-
-
-
-
homogentisicase
-
-
-
-
HTO
-
-
-
-
CAS REGISTRY NUMBER
COMMENTARY
9029-49-6
-
ORGANISM
COMMENTARY
LITERATURE
SEQUENCE CODE
SEQUENCE DB
SOURCE
Agave toumeyana
-
-
-
Manually annotated by BRENDA team
Aspergillus niger UBC 814
UBC 814
-
-
Manually annotated by BRENDA team
gene HGD
UniProt
Manually annotated by BRENDA team
Bos taurus Chinese red cattle
-
UniProt
Manually annotated by BRENDA team
genes hmgA1 and hmgA2
-
-
Manually annotated by BRENDA team
filamentous ascomycete; strain biA1
Uniprot
Manually annotated by BRENDA team
filamentous ascomycete; strains biA1 and veA1
-
-
Manually annotated by BRENDA team
Emericella nidulans BiA1
strain biA1
Uniprot
Manually annotated by BRENDA team
normal and alkaptonuric mice, which completely lack HTO
-
-
Manually annotated by BRENDA team
male rabbits
-
-
Manually annotated by BRENDA team
var. nanus
-
-
Manually annotated by BRENDA team
Pigeon
-
-
-
Manually annotated by BRENDA team
synthesis of homogentisate-1,2-dioxygenase (HmgA) is highly induced in anaerobic norCB bacteria, and not detected in wild-type extracts
-
-
Manually annotated by BRENDA team
strain KT 2440
-
-
Manually annotated by BRENDA team
Pseudomonas putida KT 2440
strain KT 2440
-
-
Manually annotated by BRENDA team
Pseudomonas putida KT2400
-
UniProt
Manually annotated by BRENDA team
Vitis vinifera x Vitis riparia
-
-
-
Manually annotated by BRENDA team
Vitis vinifera x Vitis vinifera
-
-
-
Manually annotated by BRENDA team
GENERAL INFORMATION
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
evolution
-
the G161R natural mutation in the HGD gene occurs in a Hungarian population, originating from Slovakia, resists over 300 years, alkaptonuria phenotype overview
evolution
Q88E47
despite different folds, active site architectures, and Fe2+ coordination, extradiol dioxygenases can proceed through the same principal reaction intermediatesto catalyze the O2-dependent cleavage of aromatic rings. Convergent evolution of nonhomologous enzymes using the 2-His-1-carboxylate facial triad motif developed different solutions to stabilize closely related intermediates in unlike environments
evolution
Pseudomonas putida KT2400
-
despite different folds, active site architectures, and Fe2+ coordination, extradiol dioxygenases can proceed through the same principal reaction intermediatesto catalyze the O2-dependent cleavage of aromatic rings. Convergent evolution of nonhomologous enzymes using the 2-His-1-carboxylate facial triad motif developed different solutions to stabilize closely related intermediates in unlike environments
-
malfunction
-
alkaptonuria is a rare autosomal recessive disease, associated with deficiency of homogentisate 1,2-dioxygenase activity in the liver. This leads to an accumulation of homogentisic acid and its oxidized derivatives in polymerized form in connective tissues, especially in joints. Homogentisic acid induces apoptosis in chondrocytes. N-acetylcysteine decreases apoptosis induced in chondrocytes by HGA, increases chondrocyte growth reduced by homogentisate, and partially restores proteoglycan release inhibited by homogentisate, the effect is improved by addition of ascorbic acid. Evaluation of antioxidant drugs for the treatment of ochronotic alkaptonuria, caused by homogentisate 1,2-dioxygenase activity mutation, in an in vitro human cell model, overview
malfunction
-
alkaptonuria results from defective homogentisate1,2-dioxygenase, causing degenerative arthropathy. The deposition of ochronotic pigment in joints is so far attributed to homogentisic acid produced by the liver, circulating in the blood and accumulating locally. Alkaptonuria osteoarticular cells produce the ochronotic pigment in loco and this may strongly contribute to induction of ochronotic arthropath
malfunction
-
enzyme mutations in the homogentisate 1,2 dioxygenase gene are responsible for alkaptonuria in patients among Jordanian population, genotyping, overview
physiological function
Vitis vinifera x Vitis riparia, Vitis vinifera x Vitis vinifera
-
involved in aromatic amino acid metabolism
physiological function
Q88E47
homogentisate 1,2-dioxygenase uses a mononuclear nonheme Fe2+ to catalyze the oxidative ring cleavage in the degradation of Tyr and Phe by producing maleylacetoacetate from homogentisate, i.e 2,5-dihydroxyphenylacetate
physiological function
Pseudomonas putida KT2400
-
homogentisate 1,2-dioxygenase uses a mononuclear nonheme Fe2+ to catalyze the oxidative ring cleavage in the degradation of Tyr and Phe by producing maleylacetoacetate from homogentisate, i.e 2,5-dihydroxyphenylacetate
-
metabolism
-
the enzyme is involved in tyrosine catabolism
additional information
B8YB76
HGD-BstXI genotypes show significant effects on cooking loss, drip loss, net meat weight, carcass weight, and eye muscle area. Also the HGD-HaeIII genotypes significantly affect cooking loss, muscle fibre diameter, shear force, drip loss, and carcass yield ratio. Phenotypes, overview
additional information
-
mutations in homogentisate 1,2-dioxygenase cause alkaptonuria and subsequent ochronosis, an uncommon cause of backache. The phenotype includes limited spine mobility and chronic disk degeneration, overview
additional information
Q88E47
the active site pocket with its Fe2+ ion is freely accessible from the outside through a wide opening. Homogentisate binds as a monodentate ligand to Fe2+, and its interaction with Tyr346 invokes the folding of a loop over the active site, effectively shielding it from solvent. Binding of homogentisate is driven by enthalpy and is entropically disfavored as shown by anoxic isothermal titration calorimetry. Three different reaction cycle intermediates, i.e. superoxo:semiquinone-, alkylperoxo-, and product-bound intermediates. central role of Y346 in substrate binding and turnover
additional information
Bos taurus Chinese red cattle
-
HGD-BstXI genotypes show significant effects on cooking loss, drip loss, net meat weight, carcass weight, and eye muscle area. Also the HGD-HaeIII genotypes significantly affect cooking loss, muscle fibre diameter, shear force, drip loss, and carcass yield ratio. Phenotypes, overview
-
additional information
Pseudomonas putida KT2400
-
the active site pocket with its Fe2+ ion is freely accessible from the outside through a wide opening. Homogentisate binds as a monodentate ligand to Fe2+, and its interaction with Tyr346 invokes the folding of a loop over the active site, effectively shielding it from solvent. Binding of homogentisate is driven by enthalpy and is entropically disfavored as shown by anoxic isothermal titration calorimetry. Three different reaction cycle intermediates, i.e. superoxo:semiquinone-, alkylperoxo-, and product-bound intermediates. central role of Y346 in substrate binding and turnover
-
SUBSTRATE
PRODUCT                      
REACTION DIAGRAM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
(Substrate)
LITERATURE
(Substrate)
COMMENTARY
(Product)
LITERATURE
(Product)
Reversibility
r=reversible
ir=irreversible
?=not specified
3-chlorohomogentisate + O2
3-chloro-4-maleylacetoacetate
show the reaction diagram
-
1% of activity with homogentisate
-
-
?
3-methylhomogentisate + O2
3-methyl-4-maleylacetoacetate
show the reaction diagram
-
10% of activity with homogentisate
-
-
?
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
-
-
-
?
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
-
-
-
?
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
-
-
-
?
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
-
-
-
?
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
-
-
-
ir
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
Q93099
-
-
?
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
-
-
-
?
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
-
-
-
-
?
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
-
-
-
-
ir
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
-
-
-
?
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
Q00667
-
-
?
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
-
-
-
?
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
-
-
-
?
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
-
-
-
-
ir
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
-
-
-
?
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
-
-
-
-
ir
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
-
-
-
?
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
-
-
-
-
?
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
Q9ZRA2
-
-
-
ir
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
-
-
-
-
?
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
Q88E47
-
-
-
?
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
-
-
product is 4-maleylacetoacetate, which is converted by a specific cis-trans isomerase to 4-fumarylacetoacetate
?
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
-
utilizes a nonheme iron to incorporate both atoms of molecular oxygen into homogentisate, identical with 2,5-dihydroxyphenylacetate
-
?
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
-
highly specific for homogentisate
-
?
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
-
specific for homogentisate
-
?
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
-
specific for homogentisate
-
?
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
-
homogentisate is the natural substrate, key reaction in the catabolic pathway of aromatic amino acids, oxidative cleavage of the aromatic ring
-
ir
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
-
enzyme catalyzes an intermediate step in the catabolism of tyrosine and phenylalanine
-
-
?
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
-
enzyme cleaves the aromatic ring during the metabolic degradation of phenylalanine and tyrosine
-
-
?
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
-
homogentisate catabolism
-
-
?
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
-
homogentisate ring-cleavage pathway, key enzyme of the ring-cleavage reaction in the catabolic sequence of enzymes from L-tyrosine to acetoacetate and fumarate
-
-
?
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
-
one of the key enzymes involved in catabolism of phenylalanine, tyrosine, phenylacetic acid and hydroxyphenylacetic acids
-
-
?
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
-
one of the enzymes mediating phenylalanine catabolism
-
-
?
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
Q00667
catalyzes an essential step in phenylalanine catabolism
-
-
?
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
-, Q6JDV6
ElHDO expression is induced during growth on ethylbenzene
-
-
?
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
-
hmgA is necessary for tyrosine catabolism and the proper production of actinorhodin. Transcription of hmgA is activated by HpdA in the presence of tyrosine
-
-
?
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
Aspergillus niger UBC 814
-
specific for homogentisate
-
?
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
Aspergillus niger UBC 814
-
one of the key enzymes involved in catabolism of phenylalanine, tyrosine, phenylacetic acid and hydroxyphenylacetic acids
-
-
?
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
Pseudomonas putida KT 2440
-
-
-
-
ir
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
Pseudomonas putida KT2400
Q88E47
-
-
-
?
homogentisate + O2
4-fumarylacetoacetate
show the reaction diagram
-
-
-
?
homogentisate + O2
4-fumarylacetoacetate
show the reaction diagram
-
homogentisic acid is oxidatively cleaved between carbons 1 and 2 to yield 4-fumarylacetoacetic acid, enzyme requires high oxygen tension for maximal activity
-
?
additional information
?
-
-
not as substrates: salicylic acid, catechol, 2,3-dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid, 2,6-dihydroxybenzoic acid, o-hydroxyphenylacetic acid, p-hydroxyphenylacetic acid, 3,4-dihydroxyphenylacetic acid
-
-
-
additional information
?
-
-
enzyme contains essential sulfhydryl groups
-
-
-
additional information
?
-
-
not as substrates: phenylacetate, 2-hydroxyphenylacetate, 3-hydroxyphenylacetate, 4-hydroxyphenylacetate, phenylalanine, tyrosine, phenylpyruvate, gentisate
-
-
-
additional information
?
-
-
enzyme structure, conformation of the active site, enzyme contains a 280-residue N-terminal domain and a 140-residue C-terminal domain, associated as a hexamer arranged as a dimer of trimers
-
-
-
additional information
?
-
Q9ZRA2
gentisate is not a substrate
-
-
-
additional information
?
-
-
growth of the hmgA mutant on L-tyrosine as sole carbon and energy sources is impaired. Growth on L-tyrosine is restored and production of the brown melanin pigment is eliminated when the mutant is complemented with the wild-type hmgA gene. The change in aromatic amino acids metabolism caused by the deletion of the hmgA gene function does not impair production of phenazines and biological traits connected to these secondary compounds: inhibition of fungal growth and inhibition of barley seed germination
-
-
-
additional information
?
-
-
LB400 cells grown with 3-hydroxyphenylacetate degrade homogentisate and show homogentisate 1,2-dioxygenase, EC 1.13.11.5 activity
-
-
-
additional information
?
-
-
growth of the hmgA mutant on L-tyrosine as sole carbon and energy sources is impaired. Growth on L-tyrosine is restored and production of the brown melanin pigment is eliminated when the mutant is complemented with the wild-type hmgA gene. The change in aromatic amino acids metabolism caused by the deletion of the hmgA gene function does not impair production of phenazines and biological traits connected to these secondary compounds: inhibition of fungal growth and inhibition of barley seed germination
-
-
-
NATURAL SUBSTRATES
NATURAL PRODUCTS
REACTION DIAGRAM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
(Substrate)
LITERATURE
(Substrate)
COMMENTARY
(Product)
LITERATURE
(Product)
REVERSIBILITY
r=reversible
ir=irreversible
?=not specified
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
-
-
-
-
?
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
-
-
-
-
?
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
-
-
-
-
?
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
-
-
-
-
?
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
Q88E47
-
-
-
?
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
-
homogentisate is the natural substrate, key reaction in the catabolic pathway of aromatic amino acids, oxidative cleavage of the aromatic ring
-
ir
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
-
enzyme catalyzes an intermediate step in the catabolism of tyrosine and phenylalanine
-
-
?
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
-
enzyme cleaves the aromatic ring during the metabolic degradation of phenylalanine and tyrosine
-
-
?
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
-
homogentisate catabolism
-
-
?
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
-
homogentisate ring-cleavage pathway, key enzyme of the ring-cleavage reaction in the catabolic sequence of enzymes from L-tyrosine to acetoacetate and fumarate
-
-
?
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
-
one of the key enzymes involved in catabolism of phenylalanine, tyrosine, phenylacetic acid and hydroxyphenylacetic acids
-
-
?
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
-
one of the enzymes mediating phenylalanine catabolism
-
-
?
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
Q00667
catalyzes an essential step in phenylalanine catabolism
-
-
?
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
-
hmgA is necessary for tyrosine catabolism and the proper production of actinorhodin. Transcription of hmgA is activated by HpdA in the presence of tyrosine
-
-
?
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
Aspergillus niger UBC 814
-
one of the key enzymes involved in catabolism of phenylalanine, tyrosine, phenylacetic acid and hydroxyphenylacetic acids
-
-
?
homogentisate + O2
4-maleylacetoacetate
show the reaction diagram
Pseudomonas putida KT2400
Q88E47
-
-
-
?
additional information
?
-
-
growth of the hmgA mutant on L-tyrosine as sole carbon and energy sources is impaired. Growth on L-tyrosine is restored and production of the brown melanin pigment is eliminated when the mutant is complemented with the wild-type hmgA gene. The change in aromatic amino acids metabolism caused by the deletion of the hmgA gene function does not impair production of phenazines and biological traits connected to these secondary compounds: inhibition of fungal growth and inhibition of barley seed germination
-
-
-
additional information
?
-
-
LB400 cells grown with 3-hydroxyphenylacetate degrade homogentisate and show homogentisate 1,2-dioxygenase, EC 1.13.11.5 activity
-
-
-
additional information
?
-
-
growth of the hmgA mutant on L-tyrosine as sole carbon and energy sources is impaired. Growth on L-tyrosine is restored and production of the brown melanin pigment is eliminated when the mutant is complemented with the wild-type hmgA gene. The change in aromatic amino acids metabolism caused by the deletion of the hmgA gene function does not impair production of phenazines and biological traits connected to these secondary compounds: inhibition of fungal growth and inhibition of barley seed germination
-
-
-
COFACTOR
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
IMAGE
ascorbate
Q9ZRA2
-
METALS and IONS
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
Fe2+
-
ferrous ion is required for maximal activity at pH 7 and pH 5.3; ferrous mercaptans at the active center
Fe2+
-
Fe2+ is required as cofactor
Fe2+
-
contains non-porphyrin iron, valence change of enzymic iron during reaction: ferric and ferrous iron
Fe2+
-
requires Fe2+
Fe2+
-
dependent on the presence of Fe2+
Fe2+
Q00667
70% reduction of enzyme activity in crude extract in absence of Fe2+ and absolutely requirement for Fe2+ of the fusion protein of homogentisate dioxygenase and glutathione S-transferase, expressed in Escherichia coli
Fe2+
-
-
Fe2+
-
contains a nonheme Fe2+ at the active site, that is coordinated near the interface between subunits in the HGO trimer by Glu-341, His-335 and His-371
Fe2+
-
-
Fe2+
-
Fe2+ is an absolutely obligate cofactor and cannot be replaced by other divalent cations, highest enzyme activity in vitro at 2 mM Fe2+
Fe2+
-
required for activity
Fe2+
-
required
Fe2+
Q88E47
required, ferrous ion content of 0.56 mol of iron per mol of protein, all twelve subunits in the a.u. contain fully occupied Fe sites, octahedral coordination for Fe2+ with two histidine residues (His331 and His367), the enzyme uses a mononuclear nonheme Fe2+ to catalyze the oxidative ring cleavage in the degradation of Tyr and Phe by producing maleylacetoacetate from homogentisate
additional information
-
other metallic ions, such as Fe3+, Co2+, Mn2+, Cu+ and Cu2+, cannot replace Fe2+
additional information
-
Fe3+ cannot replace Fe2+
INHIBITORS
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
IMAGE
1,10-phenanthroline
-
inactivation in the absence of O2 due to formation of a white precipitate corresponding to apoprotein
2,2'-dipyridyl
-
complete inhibition
2,2'-dipyridyl
-
5 mM, complete inhibition
2-hydroxyphenylacetate
-
strong competitive inhibition with respect to homogentisate
2-mercaptoethanol
-
-
3,4-Dihydroxyphenylacetate
-
1 mM, 48% inhibition, substrate analogue
3-chlorohomogentisate
-
inactivation in the presence of O2 due to formation of a white precipitate corresponding to apoprotein
3-hydroxyphenylacetate
-
competitive inhibition with respect to homogentisate
ascorbate
-
strong inhibitory effect, but stabilizes
ascorbic acid
-
38% inhibition at pH 6.2
benzoquinoneacetic acid
-
-
-
CaCl2
-
0.001 mM, 56% inhibition
Co2+
-
incubation with Fe2+ plus Co2+ in equimolar concentrations inhibits
Cu2+
-
incubation with Fe2+ plus Cu2+ in equimolar concentrations inhibits
cyanide
-
3 mM inhibits
cysteic acid
-
weak inhibition
cysteine
-
inhibition not reversed by glutathione
cystine
-
inhibition not reversed by glutathione
FeSO4
-
0.25 mM, 42% inhibition
glutathione
-
reduced glutathione slightly inhibits
Hg2+
-
inhibition reversed by glutathione
HgCl2
-
20 mM, complete inhibition
Lewisite
-
inhibits by competing with Fe2+ for a common enzymic binding site
NaCl
-
0.001 mM, 63% inhibition
Ni2+
-
incubation with Fe2+ plus Ni2+ in equimolar concentrations inhibits
p-chloromercuribenzoate
-
inhibits by competing with Fe2+ for a common enzymic binding site
p-chloromercuribenzoate
-
competitive inhibition with respect to Fe2+ but not to homogentisate
p-chloromercuribenzoate
-
inhibition reversed by glutathione
p-hydroxyphenylacetic acid
-
80 mM, complete inhibition, substrate analogue
p-hydroxyphenylpyruvate
-
1 mM, 68% inhibition, substrate analogue
sulfhydryl reagents
-
strong inhibition
Superoxide dismutase
-
inhibits the reaction indicating the involvement of superoxide anions in the dioxygenase reaction
-
Zn2+
-
incubation with Fe2+ plus Zn2+ in equimolar concentrations inhibits
Methylmercuric bromide
-
inhibits by competing with Fe2+ for a common enzymic binding site
additional information
-
not inhibited by Ca2+ and Mn2+
-
ACTIVATING COMPOUND
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
IMAGE
4-Hydroxy-3-methoxybenzaldehyde
-
2 mM
ascorbate
-
required for maximal activity at pH 7
ascorbate
-
required for maximal activity at pH 6
ascorbate
-
activates
ascorbate
-
dependent on the presence of ascorbate, presumably to maintain iron in the reduced form
cysteine
-
activates
cysteine
-
activates
glutathione
-
reduced glutathione is required for maximal activity at pH 7
glutathione
-
required for maximal activity at pH 6 and 5.4
glutathione
-
activates
additional information
-
pH 7.0: a combination of ascorbate, reduced glutathione and ferrous iron is required for activation, pH 5.3: ferrous iron alone fully activates
-
additional information
-
enzymes of phenylalanine catabolism including HGO are strongly induced by the presence of phenylalanine or phenylacetate
-
additional information
Q00667
fusion protein of homogentisate dioxygenase and glutathione S-transferase, expressed in Escherichia coli is fully active in absence of ascorbate
-
additional information
-
induced gene expression by water deficit
-
KM VALUE [mM]
KM VALUE [mM] Maximum
SUBSTRATE
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
IMAGE
0.009
-
Homogentisate
-
-
0.009
-
Homogentisate
-
25C, pH 8.0
0.01
-
Homogentisate
-
-
0.014
-
Homogentisate
-
37C, pH 7.0
0.015
-
Homogentisate
-
37C, pH 6.2
0.016
-
Homogentisate
-
25C, pH 7.0
0.022
-
Homogentisate
-
25C, pH 6.2
0.031
-
Homogentisate
Q9ZRA2
in the absence of ascorbate and Fe2+
0.042
-
Homogentisate
-
25C, pH 5.5
0.0532
-
Homogentisate
Q88E47
pH not specified in the publication, 25C, wild-type enzyme
0.188
-
Homogentisate
-
-
0.6
-
Homogentisate
-
at pH 6
0.6
-
Homogentisate
-
-
TURNOVER NUMBER [1/s]
TURNOVER NUMBER MAXIMUM[1/s]
SUBSTRATE
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
IMAGE
0.53
-
3-chlorohomogentisate
-
25C, pH 6.2
5.3
-
3-methylhomogentisate
-
25C, pH 6.2
10.1
-
Homogentisate
-
25C, pH 8.0
32.2
-
Homogentisate
-
25C, pH 7.0
41.5
-
Homogentisate
-
25C, pH 5.5
43.4
-
Homogentisate
-
37C, pH 7.0
56
-
Homogentisate
-
25C, pH 6.2
64.3
-
Homogentisate
-
37C, pH 6.2
79.5
-
Homogentisate
Q88E47
pH not specified in the publication, 25C, wild-type enzyme
kcat/KM VALUE [1/mMs-1]
kcat/KM VALUE [1/mMs-1] Maximum
SUBSTRATE
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
IMAGE
4.6
-
Homogentisate
Q88E47
pH not specified in the publication, 25C, mutant Y346F
11457
5038
-
Homogentisate
Q88E47
pH not specified in the publication, 25C, wild-type enzyme
11457
SPECIFIC ACTIVITY [µmol/min/mg]
SPECIFIC ACTIVITY MAXIMUM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
0.125
-
-
-
0.25
-
-
-
0.39
-
-
-
0.495
-
-
-
0.625
-
Agave toumeyana
-
-
0.75
1
-
value in crude lysates
28.3
-
-
recombinant HGO
additional information
-
-
-
additional information
-
-
-
additional information
-
-
-
pH OPTIMUM
pH MAXIMUM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
6.1
-
-
-
6.2
-
-
Good buffer
pH RANGE
pH RANGE MAXIMUM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
5
8
-
approx. 15% of maximal activity at pH 5.0 and pH 8.0, respectively
TEMPERATURE OPTIMUM
TEMPERATURE OPTIMUM MAXIMUM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
25
-
Q88E47
assay at
38
-
-
assay at
pI VALUE
pI VALUE MAXIMUM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
5.74
-
-
calculated value
6.7
-
-
theoretical value
SOURCE TISSUE
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
SOURCE
-
expression of HGO gene
Manually annotated by BRENDA team
-
primary culture, alkaptonuria chondrocytes show a 10% increase of the enzyme expression compared to normal ones
Manually annotated by BRENDA team
-
liver from a 20 week old male embryo
Manually annotated by BRENDA team
-
expression of HGO gene
Manually annotated by BRENDA team
-
less activity than in liver or in rat kidney
Manually annotated by BRENDA team
-
40% of enzyme activity in liver
Manually annotated by BRENDA team
-
expression of HGO gene
Manually annotated by BRENDA team
-
higher activity than in kidney
Manually annotated by BRENDA team
-
embryonal liver
Manually annotated by BRENDA team
-
expression of HGO gene
Manually annotated by BRENDA team
-
expression of HGO gene
Manually annotated by BRENDA team
-
expression of HGO gene
Manually annotated by BRENDA team
-
expression of HGO gene
Manually annotated by BRENDA team
additional information
-
not in heart
Manually annotated by BRENDA team
additional information
-
not in cardiac and skeletal muscle, brain, spleen, intestine, pancreas, salivary gland, germinal epithelium, blood
Manually annotated by BRENDA team
additional information
B8YB76
tissue distribution of HGD, semi-quantitative RT-PCR analysis, overview
Manually annotated by BRENDA team
additional information
-
enzyme expression analysis in human normal and alkaptonuria chondrocytes, synoviocytes, osteoblasts as well as in human osteosarcoma cells, overview
Manually annotated by BRENDA team
LOCALIZATION
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
GeneOntology No.
LITERATURE
SOURCE
PDB
SCOP
CATH
ORGANISM
Pseudomonas putida (strain KT2440)
Pseudomonas putida (strain KT2440)
Pseudomonas putida (strain KT2440)
MOLECULAR WEIGHT
MOLECULAR WEIGHT MAXIMUM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
48000
-
-
SDS-PAGE
52900
-
-
theoretical value
149000
-
-
gel filtration
150000
-
-
-
199000
-
Q9ZRA2
gel filtration
200000
-
-
gel filtration
254000
-
-
-
380000
-
-
ultracentrifugal analysis
424000
478000
-
equilibrium sedimentation studies
450000
480000
-
sucrose density gradient centrifugation, can be degraded in two proteins of 200 and 230 kDa, probably due to inactivation by air
SUBUNITS
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
?
-
x * 49000, SDS-PAGE
?
Q00667
x * 50168, calculated from the amino acid sequence
hexamer
-
hexamer arranged as a dimer of trimers, subunit structure, functional importance of the hexamer in vivo
hexamer
-
6 * 50150, mass spectrometry
homohexamer
-
or dimer of trimer, X-ray crystallography
monomer
-
1 * 450000-480000, SDS-PAGE
tetramer
Q9ZRA2
4 * 49750, gel filtration
trimer
-
3 * 49000, SDS-PAGE
POSTTRANSLATIONAL MODIFICATION
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
no glycoprotein
-
enzyme is not glycosylated
Crystallization/COMMENTARY
ORGANISM
UNIPROT ACCESSION NO.
LITERATURE
crystal structures of apo-HGO and HGO containing an iron
-
three crystal structures of the enzyme, revealing five different steps in its reaction cycle, crystallization of purifed recombinant wild-type aand mutant enzymes, mixing of 15 mg/ml protein solution with an equal volume of reservoir solution containing 16-17% PEG 3350, 0.02 M Na,K phosphate, and 0.1 M Bis-Tris propane, pH 8.0, with or without 2 mM homogentisate, vapour diffusion method, X-ray diffraction structure determination and analysis at 1.7-1.98 A resolution
Q88E47
pH STABILITY
pH STABILITY MAXIMUM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
6
7.2
-
-20C, stable for several weeks
TEMPERATURE STABILITY
TEMPERATURE STABILITY MAXIMUM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
25
55
-
almost linear decrease of activity
37
-
-
50% loss of activity after 17 s, pH 7.0; 50% loss of activity after 28 s, pH 6.2
45
-
-
65% loss of activity
GENERAL STABILITY
ORGANISM
UNIPROT ACCESSION NO.
LITERATURE
10% acetone stabilizes
-
rather stable enzyme, can be repeatedly thawed and frozen without significant loss of activity
-
ascorbate stabilizes, it probably protects Fe2+ from spontaneous oxidation
-
unlike the mammalian enzyme, the bacterial enzyme is fairly stable on aging or during storage
-
OXIDATION STABILITY
ORGANISM
UNIPROT ACCESSION NO.
LITERATURE
Fe2+, organic mercurials and reducing agents protect the enzyme from irreversible aerobic oxidation
-
396333
inactivation by air probably causes degradation of enzyme in two proteins
-
439390
sensitive to O2, easily inactivated by aeration
-
439380
STORAGE STABILITY
ORGANISM
UNIPROT ACCESSION NO.
LITERATURE
4C, 20 mM Tris-Cl pH 7.8, 0.5 M NaCl, 0.3 M imidazole, 24 h, loses two third of its activity
Q9ZRA2
-20C, in absence of Fe2+, about 3 days, stable
-
-20C, 50 mM potassium phosphate buffer, pH 7.0, crude extracts, 5 months, 25% loss of activity
-
-80, 20 mM Hepps, pH 8.0, 100 mM NaCl, 4 months, no loss of activity
-
-20C, pH 6.0-7.2, in absence of Fe2+, several weeks, stable
-
Purification/COMMENTARY
ORGANISM
UNIPROT ACCESSION NO.
LITERATURE
partial purification
Agave toumeyana, Agrostemma githago
-
nickel chelate affinity chromatography
Q9ZRA2
19.2fold purification
-
partial purification
-
partial purification
-
190fold purification
-
purification of a fusion protein of homogentisate dioxygenase and glutathione S-transferase, expressed in Escherichia coli
Q00667
partial purification
-
recombinant His-tagged HGO, Ni-affinity, Mono Q
-
partial purification
-
330fold purification
-
partial purification
-
54.1fold purification
-
recombinant wild-type and mutant enzymes from Escherichia coli strain BL21(DE3) by anion exchange and hydroxyapatite chromatography
Q88E47
Superdex gel filtration and Q-Sepharose column chromatography
-
partial purification
-
Cloned/COMMENTARY
ORGANISM
UNIPROT ACCESSION NO.
LITERATURE
expressed in Escherichia coli
Q9ZRA2
DNA and amino acid sequence determination and analysis, genotyping, polymorphism of the HGD gene in the exon 1 and intron 1
B8YB76
gene HGD, DNA and amino acid sequence determination and analysis, genotyping, semi-quantitative RT-PCR analysis. Identification of nine single nucleotide polymorphisms, five in the coding region and four intronic
B8YB76
genes hmgA1 and hmgA2, the gene cluster hmgABC is located at C1 in strain LB400 genome, quantitative expression analysis
-
hmgA gene encoding homogentisate dioxygenase, a 448 residue polypeptide, is cloned, sequenced and characterized, gene is expressed in Escherichia coli as a fusion to glutathione S-transferase
Q00667
DNA and ammino acid sequence determinaation and analysis, located on chromosome 3(q23-3q21), genotyping and identification of narurally occuring mutations involved in alkaptonuria, overview
-
expression of His-tagged HGO in Escherichia coli
-
genotyping
-
HGO gene on chromosome 3 is cloned, completely sequenced and characterized, identification of its promoter region, transcriptional control of the gene
-
PCR of coding region of DNA extracted from EDTA blood sample
-
complete HGO cDNA, encoding for a 50 kDa protein, is cloned and sequenced
-
expression of wild-type and mutant enzymes in Escherichia coli strain BL21(DE3)
Q88E47
EXPRESSION
ORGANISM
UNIPROT ACCESSION NO.
LITERATURE
induction of fumarylacetoacetate hydrolase HmgB in Burkholderia xenovorans LB400 during growth on hydroxyphenylacetates
-
LB400 cells grown with 3-hydroxyphenylacetate degrade homogentisate and show homogentisate 1,2-dioxygenase activity. The hmgA1 gene is upregulated by 3-hydroxyphenylacetate in strain LB400. The expression of the hmgA2 gene is induced in 3-hydroxyphenylacetategrown-cells
-
ENGINEERING
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
C1273A
-
naturally occuring mutation, the mutation is involved in alkaptonuria
G161R
-
naturally occuring mutation in the HGD gene, resulting in a specific genotype appearing in a Hungarian population, originating from Slovakia, with alkaptonuria, phenotype overview
G360R
-
active site mutation in exon 13
T1046G
-
naturally occuring mutation, the mutation is involved in alkaptonuria
T533G
-
naturally occuring mutation, the mutation is involved in alkaptonuria
H288Q
Q88E47
site-directed mutagenesis, the mutant shows a 75fold reduction in kcat compared to the wild-type enzyme
Y346F
Q88E47
site-directed mutagenesis, replacement of Y346 by phenylalanine decreases the affinity for homogentisate more than 60fold and reduces the apparent kcat 20fold resulting in a decrease of the specificity constant by three orders of magnitude compared to the wild-type enzyme
H288Q
Pseudomonas putida KT2400
-
site-directed mutagenesis, the mutant shows a 75fold reduction in kcat compared to the wild-type enzyme
-
Y346F
Pseudomonas putida KT2400
-
site-directed mutagenesis, replacement of Y346 by phenylalanine decreases the affinity for homogentisate more than 60fold and reduces the apparent kcat 20fold resulting in a decrease of the specificity constant by three orders of magnitude compared to the wild-type enzyme
-
additional information
-
strain carrying an homogentisate dioxygenase gene disruption with full genotype biA1, methG1, deltahmgA without enzyme activity
additional information
Q00667
mutant strain biA1, methG1, argB2 with homogentisate dioxygenase gene disruption has no homogentisate dioxygenase activity and accumulates homogentisate
K57N
-
active site mutation in exon 3
additional information
-
alkaptonuric humans are deficient for homogentisate 1,2-dioxygenase and carry two copies of a loss-of-function allele of HGO gene
additional information
-
human gene for alkaptonuria is mapped to chromosome 3q2
additional information
-
20 missence mutations in HGO from alkaptonuria patients
additional information
-
the 551-552insG mutation is involved in alkaptonuria
T847C
-
naturally occuring mutation, the mutation is involved in alkaptonuria
additional information
-
alkaptonuric mouse lacks enzyme activity and have recessive mutation aku, mapped to chromosome 16, inbred strain C57BLG/J is heterozygous for the aku mutation
additional information
-
-
APPLICATION
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
diagnostics
-
crude enzyme preparations can be used for a spectrophotometric method for routine, sensitive determination of homogentisate in human urine
medicine
-
alkaptonuria: rare hereditary disorder of the phenylalanine catabolism, patients are deficient in homogentisate 1,2-dioxygenase and carry two copies of a loss-of-function allele of HGO gene, disease causes homogentisic aciduria, ochronosis and arthritis
medicine
-
inactivation of enzyme in kidney and liver causes the basic defect of alkaptonuria
medicine
-
HGO deficiency causes alkaptonuria, inherited as a recessive Mendelian trait, HGO inhibitors may be useful in the treatment of hereditary tyrosinemia type I, HT1
medicine
-
missense mutation in exon 13 (G360R) and exon 3 (K57N) affecting homogentisate 1,2-dioxygenase function by interfering with substrate traffic at active site causing alkaptonuria, a rare recessive phanylalanine/tyrosine metabolism disorder
medicine
-
HGO gene is responsible for alkaptonuria
medicine
-
-