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Information on EC 2.6.1.13 - ornithine aminotransferase and Organism(s) Mus musculus and UniProt Accession P29758
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2.6.1.13 ornithine aminotransferaseIUBMB Comments
A pyridoxal-phosphate protein.
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Word Map
- 2.6.1.13
- atrophy
-
gyrate
- arginase
- retina
- choroid
- pyridoxal
- polyamines
-
chorioretinal
-
hyperornithinemia
- citrulline
- putrescine
-
transamination
- aminotransferases
- delta1-pyrroline-5-carboxylate
- 1-pyrroline-5-carboxylate
- argininosuccinate
- gabaculine
-
hyperammonemias
- carbamoylphosphate
- biotechnology
- medicine
-
plp-dependent
- analysis
- drug development
- diagnostics
- agriculture
The taxonomic range for the selected organisms is: Mus musculus
The expected taxonomic range for this enzyme is: Eukaryota, Bacteria, Archaea
The expected taxonomic range for this enzyme is: Eukaryota, Bacteria, Archaea
Reaction Schemes
Synonyms
ornithine aminotransferase, ornithine-delta-aminotransferase, ornithine transaminase, ornithine delta-aminotransferase, psoat, delta-oat, ornithine amino transferase, l-ornithine:2-oxoacid aminotransferase, ornithine delta-transaminase, taoat, 
more
topSYNONYM 
ORGANISM
UNIPROT
COMMENTARY 
LITERATURE
aminotransferase, ornithine-keto acid
-
-
-
-
L-ornithine 5-aminotransferase
-
-
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L-ornithine aminotransferase
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-
-
-
L-ornithine:alpha-ketoglutarate delta-aminotransferase
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-
-
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OAT
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-
-
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ornithine 5-aminotransferase
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-
-
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ornithine aminotransferase
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-
-
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ornithine delta-transaminase
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-
-
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ornithine transaminase
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-
-
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ornithine-2-oxoacid aminotransferase
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-
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ornithine-alpha-ketoglutarate aminotransferase
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-
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ornithine-keto acid aminotransferase
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-
-
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ornithine-keto acid transaminase
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-
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ornithine-ketoglutarate aminotransferase
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-
-
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ornithine-oxo acid aminotransferase
-
-
-
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ornithine-oxo-acid transaminase
-
-
-
-
ornithine:alpha-oxoglutarate transaminase
-
-
-
-
REACTION
REACTION DIAGRAM
COMMENTARY
ORGANISM
UNIPROT
LITERATURE
L-ornithine + a 2-oxo carboxylate = L-glutamate 5-semialdehyde + an L-amino acid
the enzyme performs a OAT-like PLP-dependent transaminase ping-pong mechanism, two half-reactions completing a full transamination cycle. Like other transaminases, ornithine delta-aminotransferase in the absence of substrates forms an internal aldimine with the PLP cofactor covalently bound on a lysine residue through a Schiff base. In the first half-reaction, ornithine forms an external aldimine with PLP, no longer covalently bound to the enzyme, but retained in the active site through non-covalent interactions. Enzyme OAT thus acts as an omega-transaminase in the first half-reaction, and as an alpha-transaminase in the second half-reaction: although the alpha-amino group is more reactive then the distal one, in the first half-reaction OAT transaminates the distal OAT amino group
REACTION TYPE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
amino group transfer
-
-
-
-
PATHWAY SOURCE
PATHWAYS
BRENDA
-
-, -, -, -, -, -, -
SYSTEMATIC NAME
IUBMB Comments
L-ornithine:2-oxo-acid aminotransferase
A pyridoxal-phosphate protein.
CAS REGISTRY NUMBER
COMMENTARY
9030-42-6
-
SUBSTRATE
PRODUCT
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate)
(Substrate)
LITERATURE
(Substrate)
(Substrate)
COMMENTARY
(Product)
(Product)
LITERATURE
(Product)
(Product)
Reversibility
r=reversible
ir=irreversible
?=not specified
r=reversible
ir=irreversible
?=not specified
L-ornithine + 2-oxoglutarate
DELTA1-pyrroline-5-carboxylate + L-glutamate
-
-
-
?
L-ornithine + 2-oxoglutarate
DELTA1-pyrroline-5-carboxylate + L-glutamate
-
-
-
-
?
L-ornithine + 2-oxoglutarate
glutamate + DELTA1-pyrroline-5-carboxylate
-
-
-
-
?
additional information
?
-
spontaneous cyclization of glutamate 5-semialdehyde (GSA) to form (S)-DELTA1-pyrroline-5-carboxylate (P5C), the aldehyde can spontaneously react to give a hydrated form of GSA, making the reaction almost irreversible in vitro
-
-
-
L-ornithine + 2-oxoglutarate
L-glutamate 5-semialdehyde + L-glutamate
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-
-
r
L-ornithine + 2-oxoglutarate
L-glutamate 5-semialdehyde + L-glutamate
the forward reaction is favoured
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-
r
NATURAL SUBSTRATE
NATURAL PRODUCT
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate)
(Substrate)
LITERATURE
(Substrate)
(Substrate)
COMMENTARY
(Product)
(Product)
LITERATURE
(Product)
(Product)
REVERSIBILITY
r=reversible
ir=irreversible
?=not specified
r=reversible
ir=irreversible
?=not specified
L-ornithine + 2-oxoglutarate
L-glutamate 5-semialdehyde + L-glutamate
-
-
-
r
COFACTOR
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
INHIBITOR
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
testosterone
ornithine aminotransferase is naturally downregulated in the presence of testosterone
KM VALUE [mM]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
0.72
2-oxoglutarate
pH and temperature not specified in the publication, liver enzyme
2.6
2-oxoglutarate
pH and temperature not specified in the publication, brain enzyme
0.8
L-ornithine
pH and temperature not specified in the publication, enzyme from cortical interneurons
1.1
L-ornithine
pH and temperature not specified in the publication, brain enzyme
1.2 - 4.8
L-ornithine
pH and temperature not specified in the publication, liver enzyme
4.3
L-ornithine
pH and temperature not specified in the publication, enzyme from astrocytes
4.7
L-ornithine
pH and temperature not specified in the publication, enzyme from cerebellar granule cells
SPECIFIC ACTIVITY [µmol/min/mg]
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
0.0000183
pH and temperature not specified in the publication, brain enzyme
0.00018
pH and temperature not specified in the publication, liver enzyme
pH OPTIMUM
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
TEMPERATURE OPTIMUM
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
ORGANISM
COMMENTARY
LITERATURE
UNIPROT
SEQUENCE DB
SOURCE
SOURCE TISSUE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
SOURCE
before puberty, ornithine aminotransferase expression is similar between female and male kidneys whereas from puberty until adulthood ornithine aminotransferase expression increases in the female kidney, becoming 2.5fold higher than in the male kidney. This sex-differential expression of ornithine aminotransferase is associated with a sex-specific distribution of enzyme along the corticopapillary axis and within the nephron. Ornithine aminotransferase is three- to fourfold more expressed in the female than the male cortex. In males, enzyme is highly expressed in the medulla, mainly in the thick ascending limbs. Renal enzyme distribution in orchidectomized mice resembles that in the females. Ovariectomy does not influence enzyme expression. Ornithine aminotransferase is naturally downregulated in the presence of testosterone
LOCALIZATION
ORGANISM
UNIPROT
COMMENTARY
GeneOntology No.
LITERATURE
SOURCE
the mitochondrial localization may control the reaction kinetics, OAT activity being apparently limited by the rate of ornithine entry into the mitochondrion
GENERAL INFORMATION
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
metabolism
the ornithine delta-transaminase, OAT, stands at the crossroads of several metabolic pathways. The role of enzyme OAT in ornithine fluxes, overview
UNIPROT
ENTRY NAME
ORGANISM
NO. OF AA
NO. OF TRANSM. HELICES
MOLECULAR WEIGHT[Da]
SOURCE
SEQUENCE
LOCALIZATION PREDICTION
The reliability class of the localization prediction ranges from 1 (very reliable) to 5 (not reliable).
The reliability class of the localization prediction ranges from 1 (very reliable) to 5 (not reliable). OAT_MOUSE
439
0
48355
Swiss-Prot
Mitochondrion (Reliability: 2)
MOLECULAR WEIGHT
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
SUBUNIT
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
CRYSTALLIZATION (Commentary)
ORGANISM
UNIPROT
LITERATURE
PROTEIN VARIANTS
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
additional information
-
transgenic mice that specifically overexpress human ornithine aminotransferase in the liver, kidneys and intestine exhibit higher enzyme activity in the liver than wild-type, but there are no differences in kinetic parameters between wild-type and transgenic animal. Ornithine aminotransferase overexpression decreases plasma and liver ornithine concentrations but does not affect glutamine or arginine homeostasis. There is an inverse relationship between ornithine levels and enzyme activity
PURIFICATION (Commentary)
ORGANISM
UNIPROT
LITERATURE
CLONED (Commentary)
ORGANISM
UNIPROT
LITERATURE
it is believed that there is only one gene for OAT, pseudo-genes are not transcribed or lead to non-functional proteins, DNA and amino acid sequence comparisons and phylogenetic analysis
APPLICATION
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
medicine
medicine
-
transgenic mice that specifically overexpress human ornithine aminotransferase in the liver, kidneys and intestine exhibit higher enzyme activity in the liver than wild-type, but there are no differences in kinetic parameters between wild-type and transgenic animal. Ornithine aminotransferase overexpression decreases plasma and liver ornithine concentrations but does not affect glutamine or arginine homeostasis. There is an inverse relationship between ornithine levels and enzyme activity
medicine
pharmacological doses of testosterone down-regulate level of enzyme protein. Variations of levels of enzyme are strongly correlated with testosteronemia. Orchidectomy increases renal level of enzyme protein. Effects are reversed by injecting physiological doses of testosterone into castrated male animals
medicine
before puberty, ornithine aminotransferase expression is similar between female and male kidneys whereas from puberty until adulthood ornithine aminotransferase expression increases in the female kidney, becoming 2.5fold higher than in the male kidney. This sex-differential expression of ornithine aminotransferase is associated with a sex-specific distribution of enzyme along the corticopapillary axis and within the nephron. Ornithine aminotransferase is three- to fourfold more expressed in the female than the male cortex. In males, enzyme is highly expressed in the medulla, mainly in the thick ascending limbs. Renal enzyme distribution in orchidectomized mice resembles that in the females. Ovariectomy does not influence enzyme expression. Ornithine aminotransferase is naturally downregulated in the presence of testosterone
REF.
AUTHORS
TITLE
JOURNAL
VOL.
PAGES
YEAR
ORGANISM (UNIPROT)
PUBMED ID
SOURCE
Daune, G.; Gerhart, F.; Seiler, N.
5-Fluoromethylornithine, an irreversible and specific inhibitor of L-ornithine:2-oxo-acid aminotransferase
Biochem. J.
253
481-488
1988
Mus musculus, Rattus norvegicus
Burcham, J.M.; Giometti, C.S.; Tollaksen, S.L.; Peraino, C.
Comparison of rat and mouse ornithine aminotransferase with respect to molecular properties and regulation of synthesis
Arch. Biochem. Biophys.
262
501-507
1988
Mus musculus, Rattus norvegicus
Levillain, O.; Diaz, J.J.; Reymond, I.; Soulet, D.
Ornithine metabolism along the female mouse nephron: localization of ornithine decarboxylase and ornithine aminotransferase
Pflugers Arch.
440
761-769
2000
Mus musculus
Lim, S.N.; Rho, H.W.; Park, J.W.; Jhee, E.C.; Kim, J.S.; Kim, H.R.
A variant of ornithine aminotransferase from mouse small intestine
Exp. Mol. Med.
30
131-135
1998
Mus musculus
Levillain, O.; Diaz, J.J.; Blanchard, O.; Dechaud, H.
Testosterone down-regulates ornithine aminotransferase gene and up-regulates arginase II and ornithine decarboxylase genes for polyamines synthesis in the murine kidney
Endocrinology
146
950-959
2005
Mus musculus (P29758), Mus musculus
Levillain, O.; Ventura, G.; Dechaud, H.; Hobeika, M.; Meseguer, A.; Moinard, C.; Cynober, L.
Sex-differential expression of ornithine aminotransferase in the mouse kidney
Am. J. Physiol. Renal Physiol.
292
F1016-F1027
2007
Mus musculus (P29758), Mus musculus
Ventura, G.; De Bandt, J.P.; Segaud, F.; Perret, C.; Robic, D.; Levillain, O.; Le Plenier, S.; Godard, C.; Cynober, L.; Moinard, C.
Overexpression of ornithine aminotransferase: consequences on amino acid homeostasis
Br. J. Nutr.
101
843-851
2009
Homo sapiens, Mus musculus
Ginguay, A.; Cynober, L.; Curis, E.; Nicolis, I.
Ornithine aminotransferase, an important glutamate-metabolizing enzyme at the crossroads of multiple metabolic pathways
Biology
6
18
2017
Geukensia demissa, Oryctolagus cuniculus (A0A5F9CII4), Salmo trutta (A0A674DA32), Pisum sativum (B1A0U3), Homo sapiens (P04181), Rattus norvegicus (P04182), Mus musculus (P29758), Vigna aconitifolia (P31893), Bos taurus (Q3ZCF5), Plasmodium falciparum (Q6LFH8)
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