2.6.1.13: ornithine aminotransferase
This is an abbreviated version!
For detailed information about ornithine aminotransferase, go to the full flat file.
Word Map on EC 2.6.1.13
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2.6.1.13
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atrophy
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gyrate
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arginase
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retina
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choroid
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pyridoxal
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polyamines
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chorioretinal
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hyperornithinemia
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citrulline
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putrescine
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transamination
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aminotransferases
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delta1-pyrroline-5-carboxylate
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1-pyrroline-5-carboxylate
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argininosuccinate
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gabaculine
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hyperammonemias
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carbamoylphosphate
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biotechnology
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medicine
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plp-dependent
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analysis
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drug development
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diagnostics
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agriculture
- 2.6.1.13
- atrophy
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gyrate
- arginase
- retina
- choroid
- pyridoxal
- polyamines
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chorioretinal
-
hyperornithinemia
- citrulline
- putrescine
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transamination
- aminotransferases
- delta1-pyrroline-5-carboxylate
- 1-pyrroline-5-carboxylate
- argininosuccinate
- gabaculine
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hyperammonemias
- carbamoylphosphate
- biotechnology
- medicine
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plp-dependent
- analysis
- drug development
- diagnostics
- agriculture
Reaction
Synonyms
aminotransferase, ornithine-keto acid, delta OAT, delta-OAT, delta-ornithine aminotransferase, deltaOAT, EC 2.6.1.68, hOAT, L-ornithine 5-aminotransferase, L-ornithine aminotransferase, L-ornithine:2-oxoacid aminotransferase, L-ornithine:alpha-ketoglutarate delta-aminotransferase, OAT, Orn-AT, ornithine 5-aminotransferase, ornithine amino transferase, ornithine aminotransferase, ornithine delta aminotransferase, ornithine delta-amino transferase, ornithine delta-aminotransferase, ornithine delta-transaminase, ornithine transaminase, ornithine-2-oxoacid aminotransferase, ornithine-alpha-ketoglutarate aminotransferase, ornithine-delta-aminotransferase, ornithine-keto acid aminotransferase, ornithine-keto acid transaminase, ornithine-ketoglutarate aminotransferase, ornithine-oxo acid aminotransferase, ornithine-oxo-acid transaminase, ornithine: 2-oxo-glutarate aminotransferase, ornithine:alpha-oxoglutarate transaminase, PsOAT, RocD, TaOAT, TaOAT-5AL, TaOAT-5B, TaOAT-5BL, TaOAT-5DL, TaOAT-AL-2, TgOAT
ECTree
2.6.1.13 ornithine aminotransferaseAdvanced search results
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results (Engineering
Engineering on EC 2.6.1.13 - ornithine aminotransferase
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PROTEIN VARIANTS 
ORGANISM
UNIPROT
COMMENTARY 
LITERATURE
E235A
mutant retains its regiospecificity for the gamma-amino group of ornithine, but the glutamate reaction is enhanced 650fold, whereas only a 5fold enhancement of the ketoglutarate reaction rate results
E235S
mutation leads to a lowering of the apparent rate and an increase of the dissociation constant
G237D
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patient with gyrate atrophy of the choroid and retina, mutation of both alleles, no enzymic activity in white blood cells. Son of patient is heterozygous for the mutation and has 45% of normal values for enzyme activity
R180T
naturally occuring, gyrate atrophy-causing mutation of ornithine delta-aminotransferase (OAT), the R180T mutation involves an active site residue located at the dimer interface, which in the crystal structure of OAT complexed with 5-fluoromethylornithine engages a salt bridge with the alpha-carboxylate of the substrate analogue. the R180T mutant exhibits a remarkable loss of catalytic activity and is endowed with the ability to catalyse not only the delta-transamination but also, albeit to a lesser extent, the alpha-transamination of L-ornithine. The slight structural changes caused by the R180T mutation, preventing a proper collocation of L-ornithine at the active site of OAT, are responsible for the notable reduction of the catalytic efficiency. Enzyme mutant structure modelling, overview
R217A
site-directed mutagenesis, the artificial dimeric mutant variant exhibits spectroscopic properties, Tm values, and catalytic features similar to those of the tetrameric species. The mutant shows increased activity compared to wild-type
Y85I
C154S
mutant shows drastically reduced activity. Activity can be activated by Trx but not to the same extent as wild-type
C154S/C163S
double mutant shows the same phenotype as mutant C154S
C163S
mutant degrades ornithine with the same specific activity as the wild-type, and the Trx-mediated activation occurres at higher Trx concentrations when compared to OAT wild-type
C316S
transamination of ornithine and 2-oxoglutarate with an activity is reduced to 25-35% of the wild-type. Mutants can be activated by Trx and reaches a specific activity comparable to PfOAT wild-type with Trx
C350S
transamination of ornithine and 2-oxoglutarate with an activity is reduced to 25-35% of the wild-type. Mutants can be activated by Trx and reaches a specific activity comparable to PfOAT wild-type with Trx
C390S
transamination of ornithine and 2-oxoglutarate with an activity is reduced to 25-35% of the wild-type. Mutants can be activated by Trx and reaches a specific activity comparable to PfOAT wild-type with Trx
V79Y
L402P
mutation based on mutant identified in humans, abrogates both OAT enzymatic activity and ability to modulate the developmental phenotype
R180T
mutation based on mutant identified in humans, abrogates both OAT enzymatic activity and ability to modulate the developmental phenotype
additional information
Y85I
mutation greatly affects the ketoglutarate reaction but has no effect on the glutamate reaction
Y85I
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mutation of Tyr85 in human OAT to Ile decreases the rate of the reaction of the enzyme with ornithine 1000fold and increases that with 4-aminobutyrate 16fold, indicating that Tyr85 is a major determinant of specificity toward ornithine
V79Y
site-directed mutagenesis, the mutation in analogy to the human enzyme causes an inversion of the substrate preference with L-ornithine becoming the preferred substrate of the V79Y variant. The V79Y mutation leads to a 6fold decrease in kcat for 2-oxoglutarate which is countered by a 6fold decrease in Km, such that kcat/Km is reduced only 1.3fold
V79Y
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site-directed mutagenesis, the mutation in analogy to the human enzyme causes an inversion of the substrate preference with L-ornithine becoming the preferred substrate of the V79Y variant. The V79Y mutation leads to a 6fold decrease in kcat for 2-oxoglutarate which is countered by a 6fold decrease in Km, such that kcat/Km is reduced only 1.3fold
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V79Y
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site-directed mutagenesis, the mutation in analogy to the human enzyme causes an inversion of the substrate preference with L-ornithine becoming the preferred substrate of the V79Y variant. The V79Y mutation leads to a 6fold decrease in kcat for 2-oxoglutarate which is countered by a 6fold decrease in Km, such that kcat/Km is reduced only 1.3fold
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additional information
functional complementation of a Saccharomyces cerevisiae mutant unable to utilize ornithine as a sole nitrogen source
additional information
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functional complementation of a Saccharomyces cerevisiae mutant unable to utilize ornithine as a sole nitrogen source
additional information
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enzyme deletion mutants accumulate urea cycle intermediates when fed with arginine or ornithine and are not able to utilize nitrogen provided as arginine or ornithine. Utilisation of urea and stress induced proline accumulation are not affected in T-DNA insertion mutants with a complete loss of ornithine aminotransferase expression
additional information
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Corynebacterium glutamicum strain 1006 is engineered to overproduce L-ornithine as a major product by inactivating regulatory repressor argR gene and overexpressing argJ gene. A genome sequence analysis indicates that the argF gene encoding ornithine carbamoyltransferase in strain 1006 is mutated, resulting in the accumulation of a certain amount of L-ornithine (20.5 g/l). The OAT activity of Corynebacterium glutamicum mutant strain 1006DELTAargR-argJ is significantly greater than that of wild-type strain 1006, showing a very high conversion ratio of sugar to acid (0.396 g/g)
additional information
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Corynebacterium glutamicum strain 1006 is engineered to overproduce L-ornithine as a major product by inactivating regulatory repressor argR gene and overexpressing argJ gene. A genome sequence analysis indicates that the argF gene encoding ornithine carbamoyltransferase in strain 1006 is mutated, resulting in the accumulation of a certain amount of L-ornithine (20.5 g/l). The OAT activity of Corynebacterium glutamicum mutant strain 1006DELTAargR-argJ is significantly greater than that of wild-type strain 1006, showing a very high conversion ratio of sugar to acid (0.396 g/g)
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additional information
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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
additional information
overexpression of OAT promoting the growth and metastasis of A549 cells. OAT knockdown in H-1299 cells transfected with OAT siRNA results in a lower expression level of OAT mRNA and protein than in the control group. Knockdown of OAT suppresses cell proliferation, decreases the number of colonies, invades cells, and migrates cells
additional information
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overexpression of OAT promoting the growth and metastasis of A549 cells. OAT knockdown in H-1299 cells transfected with OAT siRNA results in a lower expression level of OAT mRNA and protein than in the control group. Knockdown of OAT suppresses cell proliferation, decreases the number of colonies, invades cells, and migrates cells
additional information
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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
additional information
generation of an N-terminally truncated TgOAT variant lacking the first 16 residues
additional information
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generation of an N-terminally truncated TgOAT variant lacking the first 16 residues
additional information
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generation of an N-terminally truncated TgOAT variant lacking the first 16 residues
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additional information
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generation of an N-terminally truncated TgOAT variant lacking the first 16 residues
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