Information on EC 4.1.2.48 - low-specificity L-threonine aldolase

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

EC NUMBER
COMMENTARY
4.1.2.48
-
RECOMMENDED NAME
GeneOntology No.
low-specificity L-threonine aldolase
-
REACTION
REACTION DIAGRAM
COMMENTARY
ORGANISM
UNIPROT ACCESSION NO.
LITERATURE
L-allo-threonine = glycine + acetaldehyde
show the reaction diagram
-
-
-
-
L-threonine = glycine + acetaldehyde
show the reaction diagram
(1)
-
-
-
PATHWAY
KEGG Link
MetaCyc Link
glycine biosynthesis IV
-
threonine degradation IV
-
SYSTEMATIC NAME
IUBMB Comments
L-threonine/L-allo-threonine acetaldehyde-lyase (glycine-forming)
Requires pyridoxal phosphate. The low-specificity L-threonine aldolase can act on both L-threonine and L-allo-threonine [1,2]. The enzyme from Escherichia coli can also act on L-threo-phenylserine and L-erythro-phenylserine [4]. The enzyme can also catalyse the aldol condensation of glycolaldehyde and glycine to form 4-hydroxy-L-threonine, an intermediate of pyridoxal phosphate biosynthesis [3]. Different from EC 4.1.2.5, L-threonine aldolase, and EC 4.1.2.49, L-allo-threonine aldolase.
SYNONYMS
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
GLY1
P37303
gene name
L-TA
O50584
-
L-TA
O50584
-
-
L-threonine aldolase
-
-
L-threonine aldolase
-
-
low specificity L-TA
P37303
-
LtaE
-
-
-
-
LtaE
P75823
-
serine hydroxy-methyl transferase
-
-
threonine aldolase
-
-
ORGANISM
COMMENTARY
LITERATURE
SEQUENCE CODE
SEQUENCE DB
SOURCE
strain SGY269
SwissProt
Manually annotated by BRENDA team
Candida albicans SGY269
strain SGY269
SwissProt
Manually annotated by BRENDA team
GENERAL INFORMATION
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
malfunction
-, P75823
knockout of the ltaE gene of wild-type Escherichia coli does not affect the cellular growth rate, while disruption of the ltaE gene of Escherichia coli GS245, whose serine hydroxymethyltransferase gene is knocked out, causes a significant decrease in the cellular growth rate, suggesting that the threonine aldolase is not a major source of cellular glycine in wild-type Escherichia coli but catalyzes an alternative pathway for cellular glycine when serine hydroxymethyltransferase is inert
physiological function
-, P75823
threonine aldolase is not a major source of cellular glycine in wild-type Escherichia coli but catalyzes an alternative pathway for cellular glycine when serine hydroxymethyltransferase is inert
physiological function
-
low-specificity L-threonine aldolase is involved in a serendipitous pathway that converts 3-phosphohydroxypyruvate, an intermediate in the serine biosynthesis pathway, to L-4-phosphohydroxythreonine, an intermediate in the pyridoxal-5'-phosphate synthesis pathway in a strain of Escherichia coli that lacks 4-phosphoerythronate dehydrogenase
SUBSTRATE
PRODUCT                      
REACTION DIAGRAM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
(Substrate)
LITERATURE
(Substrate)
COMMENTARY
(Product)
LITERATURE
(Product)
Reversibility
r=reversible
ir=irreversible
?=not specified
3,4-dihydroxybenzaldehyde + glycine
(2S,3R,4R)-2-amino-4-(benzyloxycarbonylamino)-3-hydroxypentanoic acid
show the reaction diagram
-
conversion: 40%, glycine concentration: 70 mM, reaction temperature: 4C, yield: 30%, L-erythro/L-threo: 16:84
-
-
?
3,4-dihydroxybenzaldehyde + glycine
(2S,3R,4R)-2-amino-4-(benzyloxycarbonylamino)-3-hydroxypentanoic acid
show the reaction diagram
-
conversion: 60%, glycine concentration: 70 mM, reaction temperature: 4C, yield: 30%, L-erythro/L-threo: 100:0
-
-
?
3,4-dihydroxybenzaldehyde + glycine
(2S,3S,4R)-2-amino-4-(benzyloxycarbonylamino)-3-hydroxypentanoic acid
show the reaction diagram
-
conversion: 40%, glycine concentration: 70 mM, reaction temperature: 4C, yield: 30%, L-erythro/L-threo: 16:84
-
-
?
benzyloxyacetaldehyde + glycine
(2S,3R)-2-amino-4-(benzyloxy)-3-hydroxybutanoic acid
show the reaction diagram
-
conversion: 45%, glycine concentration: 140 mM, reaction temperature: 25C, yield: 30%, L-erythro/L-threo: 40:60
-
-
?
benzyloxyacetaldehyde + glycine
(2S,3R)-2-amino-4-(benzyloxy)-3-hydroxybutanoic acid
show the reaction diagram
-
conversion: 68%, glycine concentration: 70 mM, reaction temperature: 4C, yield: 40%, L-erythro/L-threo: 97:3
-
-
?
benzyloxyacetaldehyde + glycine
(2S,3S)-2-amino-4-(benzyloxy)-3-hydroxybutanoic acid
show the reaction diagram
-
conversion: 45%, glycine concentration: 140 mM, reaction temperature: 25C, yield: 30%, L-erythro/L-threo: 40:60
-
-
?
DL-erythro-phenylserine
glycine + benzaldehyde
show the reaction diagram
-, P75823
-
-
-
?
DL-threo-phenylserine
glycine + benzaldehyde
show the reaction diagram
-, P75823
-
-
-
?
glycine + 3,4-dihydroxybenzaldehyde
L-threo-3,4-dihydroxyphenylserine
show the reaction diagram
-
-
-
-
r
glycine + 3,4-dihydroxybenzaldehyde
L-threo-3,4-dihydroxyphenylserine
show the reaction diagram
-
L-threo-3,4-dihydroxyphenylserine synthesis activity is dramatically decreased when the condensation reaction is repeated
-
-
-
glycine + 3,4-dihydroxybenzaldehyde
L-threo-3,4-dihydroxyphenylserine + L-erythro-3,4-dihydroxyphenylserine
show the reaction diagram
-
-
-
-
r
glycine + glycolaldehyde
L-4-hydroxythreonine
show the reaction diagram
-
low-specificity L-threonine aldolase is involved in a serendipitous pathway that converts 3-phosphohydroxypyruvate, an intermediate in the serine biosynthesis pathway, to L-4-phosphohydroxythreonine, an intermediate in the pyridoxal-5'-phosphate synthesis pathway in a strain of Escherichia coli that lacks 4-phosphoerythronate dehydrogenase
-
-
r
L-4-hydroxythreonine
glycine + glycolaldehyde
show the reaction diagram
-
cleavage of L-4-hydroxythreonine is as efficient as cleavage of L-allo-threonine
-
-
r
L-allo-threonine
glycine + acetaldehyde
show the reaction diagram
-
-
-
-
r
L-allo-threonine
glycine + acetaldehyde
show the reaction diagram
-
-
-
-
r
L-allo-threonine
glycine + acetaldehyde
show the reaction diagram
P37303
-
-
-
?
L-allo-threonine
glycine + acetaldehyde
show the reaction diagram
-, P75823
-
-
-
r
L-allo-threonine
glycine + acetaldehyde
show the reaction diagram
O50584, -
-
-
-
r
L-allo-threonine
glycine + acetaldehyde
show the reaction diagram
O50584
-
-
-
r
L-erythro-phenylserine
glycine + benzaldehyde
show the reaction diagram
O50584, -
-
-
-
?
L-erythro-phenylserine
glycine + benzaldehyde
show the reaction diagram
O50584
-
-
-
?
L-phenylserine
?
show the reaction diagram
-
-
-
-
?
L-serine
glycine + formaldehyde
show the reaction diagram
-
-
-
-
?
L-Thr
Gly + acetaldehyde
show the reaction diagram
-
-
-
-
?
L-threo-3,4-dihydroxyphenylserine
glycine + 3,4-dihydroxybenzaldehyde
show the reaction diagram
-
-
-
-
?
L-threo-beta-3,4-dihydroxyphenylserine
glycine + 3,4-dihydroxybenzaldehyde
show the reaction diagram
O50584, -
-
-
-
?
L-threo-beta-3,4-dihydroxyphenylserine
glycine + 3,4-dihydroxybenzaldehyde
show the reaction diagram
O50584
-
-
-
?
L-threo-beta-3,4-methylenedioxyphenylserine
?
show the reaction diagram
O50584, -
-
-
-
?
L-threo-beta-3,4-methylenedioxyphenylserine
?
show the reaction diagram
O50584
-
-
-
?
L-threo-phenylserine
glycine + benzaldehyde
show the reaction diagram
O50584, -
-
-
-
?
L-threonine
glycine + acetaldehyde
show the reaction diagram
-
-
-
-
r
L-threonine
glycine + acetaldehyde
show the reaction diagram
-
-
-
-
r
L-threonine
glycine + acetaldehyde
show the reaction diagram
-, O13427
-
-
r
L-threonine
glycine + acetaldehyde
show the reaction diagram
P37303
-
-
-
r
L-threonine
glycine + acetaldehyde
show the reaction diagram
-, P75823
-
-
-
r
L-threonine
glycine + acetaldehyde
show the reaction diagram
O50584, -
-
-
-
r
L-threonine
glycine + acetaldehyde
show the reaction diagram
Candida albicans SGY269
O13427
-
-
r
N-(S)-benzyloxycarbonyl-alaninal + glycine
(2S,3R,4S)-2-amino-4-(benzyloxycarbonylamino)-3-hydroxypentanoic acid
show the reaction diagram
-
conversion: 48%, glycine concentration: 280 mM, reaction temperature: 4C, yield: 30%, L-erythro/L-threo: 100:0
-
-
?
N-(S)-benzyloxycarbonyl-alaninal + glycine
(2S,3R,4S)-2-amino-4-(benzyloxycarbonylamino)-3-hydroxypentanoic acid
show the reaction diagram
-
conversion: 54%, glycine concentration: 140 mM, reaction temperature: 25C, yield: 27%, L-erythro/L-threo: 18:82
-
-
?
N-(S)-benzyloxycarbonyl-alaninal + glycine
(2S,3S,4S)-2-amino-4-(benzyloxycarbonylamino)-3-hydroxypentanoic acid
show the reaction diagram
-
conversion: 54%, glycine concentration: 140 mM, reaction temperature: 25C, yield: 27%, L-erythro/L-threo: 18:82
-
-
?
N-benzyloxycarbonyl-3-aminopropanal + glycine
(2S,3R)-2-amino-5-(benzyloxycarbonylamino)-3-hydroxypentanoic acid
show the reaction diagram
-
conversion: 34%, glycine concentration: 70 mM, reaction temperature: 25C, yield: 10%, L-erythro/L-threo: 50:50
-
-
?
N-benzyloxycarbonyl-3-aminopropanal + glycine
(2S,3R)-2-amino-5-(benzyloxycarbonylamino)-3-hydroxypentanoic acid
show the reaction diagram
-
conversion: 49%, glycine concentration: 70 mM, reaction temperature: 25C, yield: 11%, L-erythro/L-threo: 50:50
-
-
?
N-benzyloxycarbonyl-3-aminopropanal + glycine
(2S,3S)-2-amino-5-(benzyloxycarbonylamino)-3-hydroxypentanoic acid
show the reaction diagram
-
conversion: 20%, glycine concentration: 70 mM, reaction temperature: 4C, yield: 3%, L-erythro/L-threo: 100:0
-
-
?
N-benzyloxycarbonyl-3-aminopropanal + glycine
(2S,3S)-2-amino-5-(benzyloxycarbonylamino)-3-hydroxypentanoic acid
show the reaction diagram
-
conversion: 49%, glycine concentration: 70 mM, reaction temperature: 25C, yield: 11%, L-erythro/L-threo: 50:50
-
-
?
N-benzyloxycarbonyl-glycinal + glycine
(2S,3R)-2-amino-4-(benzyloxycarbonylamino)-3-hydroxybutanoic acid
show the reaction diagram
-
conversion: 35%, glycine concentration: 70 mM, reaction temperature: 4C, yield: 13%, L-erythro/L-threo: 86:14
-
-
?
N-benzyloxycarbonyl-glycinal + glycine
(2S,3R)-2-amino-4-(benzyloxycarbonylamino)-3-hydroxybutanoic acid
show the reaction diagram
-
conversion: 60%, glycine concentration: 140 mM, reaction temperature: 25C, yield: 18%, L-erythro/L-threo: 30:70
-
-
?
N-benzyloxycarbonyl-glycinal + glycine
(2S,3S)-2-amino-4-(benzyloxycarbonylamino)-3-hydroxybutanoic acid
show the reaction diagram
-
conversion: 35%, glycine concentration: 70 mM, reaction temperature: 4C, yield: 13%, L-erythro/L-threo: 86:14
-
-
?
N-benzyloxycarbonyl-glycinal + glycine
(2S,3S)-2-amino-4-(benzyloxycarbonylamino)-3-hydroxybutanoic acid
show the reaction diagram
-
conversion: 60%, glycine concentration: 140 mM, reaction temperature: 25C, yield: 18%, L-erythro/L-threo: 30:70
-
-
?
L-threonine
glycine + acetaldehyde
show the reaction diagram
O50584
-
-
-
r
additional information
?
-
-, O13427
glycine metabolism
-
?
additional information
?
-
-
by manipulating reaction parameters, SHMT yields exclusively L-erythro diastereomers in 34-60% conversion. SHMT is among the most stereoselective L-threonine aldolases described. This is due to its activity-temperature dependence: at 4C SHMT has high synthetic activity but negligible retro-aldol activity on l-threonine. Thus, the kinetic l-erythro isomer is largely favored and the reactions are virtually irreversible, highly stereoselective, and in turn, give excellent conversion
-
-
-
additional information
?
-
Candida albicans SGY269
O13427
glycine metabolism
-
?
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
glycine + glycolaldehyde
L-4-hydroxythreonine
show the reaction diagram
-
low-specificity L-threonine aldolase is involved in a serendipitous pathway that converts 3-phosphohydroxypyruvate, an intermediate in the serine biosynthesis pathway, to L-4-phosphohydroxythreonine, an intermediate in the pyridoxal-5'-phosphate synthesis pathway in a strain of Escherichia coli that lacks 4-phosphoerythronate dehydrogenase
-
-
r
L-Thr
Gly + acetaldehyde
show the reaction diagram
-
-
-
-
?
additional information
?
-
-, O13427
glycine metabolism
-
?
additional information
?
-
Candida albicans SGY269
O13427
glycine metabolism
-
?
COFACTOR
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
IMAGE
pyridoxal 5'-phosphate
O50584, -
contains 1 mol of pyridoxal 5'-phosphate per mol of 38000 da subunit. Lys207 probably functions as an essential catalytic residue, forming an internal Schiff base with the pyridoxal 5'-phosphate of the enzyme to catalyze the reversible aldol reaction
pyridoxal 5'-phosphate
-
Km: 0.00025 mM, 1 mol of pyridoxal phosphate binds 46000 g of protein
pyridoxal 5'-phosphate
-
contains 6 mol of pyridoxal 5'-phosphate per mol of enzyme
pyridoxal 5'-phosphate
P37303
2 mol pyridoxal 5'-phosphate per 4 mol of subunit
pyridoxal 5'-phosphate
-, P75823
contains 1 mol of pyridoxal 5'-phosphate as cofactor per mol of 36500 Da subunit
pyridoxal 5'-phosphate
-
activates
pyridoxal 5'-phosphate
-
-
METALS and IONS
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
K+
-
K+ or NH4+ required for maximal activity
INHIBITORS
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
IMAGE
Ba2+
-
inhibited activation by K+ or NH4+
Ca2+
-
inhibited activation by K+ or NH4+
Mg2+
-
inhibited activation by K+ or NH4+
Na+
-
inhibited activation by K+ or NH4+
tetrahydrofolate
-
inhibits interconversion of L-serine and glycine
ACTIVATING COMPOUND
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
IMAGE
NH4+
-
K+ or NH4+ required for maximal activity
KM VALUE [mM]
KM VALUE [mM] Maximum
SUBSTRATE
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
IMAGE
0.24
-
DL-erythro-phenylserine
-, P75823
pH 8.0, 30C
0.12
-
DL-threo-phenylserine
-, P75823
pH 8.0, 30C
0.027
-
L-4-hydroxythreonine
-
pH 8.0, 25C
-
0.052
-
L-allo-threonine
-
pH 8.0, 25C
0.22
-
L-allo-threonine
-, P75823
pH 8.0, 30C
10
-
L-allo-threonine
P37303
pH 8.0, 30C
14.6
-
L-allo-threonine
O50584, -
pH 8.0, 30C
10.2
-
L-erythro-phenylserine
O50584, -
pH 8.0, 30C
0.000002
-
L-phenylserine
-
recombinant wild type enzyme, in 50 mM Tris-HCl buffer (pH 8.0)
0.0000026
-
L-phenylserine
-
mutant enzyme H177Y, in 50 mM Tris-HCl buffer (pH 8.0)
0.00016
-
L-Thr
-
mutant enzyme H177Y, in 50 mM Tris-HCl buffer (pH 8.0)
0.00018
-
L-Thr
-
recombinant wild type enzyme, in 50 mM Tris-HCl buffer (pH 8.0)
0.0002
-
L-threo-3,4-dihydroxyphenylserine
-
recombinant wild type enzyme, in 50 mM Tris-HCl buffer (pH 8.0)
0.00023
-
L-threo-3,4-dihydroxyphenylserine
-
mutant enzyme H177Y, in 50 mM Tris-HCl buffer (pH 8.0)
8.3
-
L-threo-beta-3,4-dihydroxyphenylserine
O50584, -
pH 8.0, 30C
7.4
-
L-threo-beta-3,4-methylenedioxyphenylserine
O50584, -
pH 8.0, 30C
7.3
-
L-threo-phenylserine
O50584, -
pH 8.0, 30C
2.85
-
L-threonine
-, P75823
pH 8.0, 30C
4
-
L-threonine
-
pH 8.0, 25C
14.7
-
L-threonine
O50584, -
pH 8.0, 30C
55
-
L-threonine
P37303
pH 8.0, 30C
TURNOVER NUMBER [1/s]
TURNOVER NUMBER MAXIMUM[1/s]
SUBSTRATE
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
IMAGE
1.44
-
L-4-hydroxythreonine
-
pH 8.0, 25C
-
3.2
-
L-allo-threonine
-
pH 8.0, 25C
41
-
L-allo-threonine
P37303
pH 8.0, 30C
0.000107
-
L-phenylserine
-
recombinant wild type enzyme, in 50 mM Tris-HCl buffer (pH 8.0)
0.000113
-
L-phenylserine
-
mutant enzyme H177Y, in 50 mM Tris-HCl buffer (pH 8.0)
0.0178
-
L-Thr
-
mutant enzyme H177Y, in 50 mM Tris-HCl buffer (pH 8.0)
0.0195
-
L-Thr
-
recombinant wild type enzyme, in 50 mM Tris-HCl buffer (pH 8.0)
0.00022
-
L-threo-3,4-dihydroxyphenylserine
-
recombinant wild type enzyme, in 50 mM Tris-HCl buffer (pH 8.0)
0.00023
-
L-threo-3,4-dihydroxyphenylserine
-
mutant enzyme H177Y, in 50 mM Tris-HCl buffer (pH 8.0)
1.1
-
L-threonine
-
pH 8.0, 25C
43
-
L-threonine
P37303
pH 8.0, 30C
kcat/KM VALUE [1/mMs-1]
kcat/KM VALUE [1/mMs-1] Maximum
SUBSTRATE
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
IMAGE
5.3
-
L-4-hydroxythreonine
-
pH 8.0, 25C
0
4.1
-
L-allo-threonine
P37303
pH 8.0, 30C
12053
6.2
-
L-allo-threonine
-
pH 8.0, 25C
12053
0.78
-
L-threonine
P37303
pH 8.0, 30C
12432
2.8
-
L-threonine
-
pH 8.0, 25C
12432
SPECIFIC ACTIVITY [µmol/min/mg]
SPECIFIC ACTIVITY MAXIMUM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
1.7
-
-, P75823
pH 8.0, 30C
2.5
-
P37303
pH 8.0, 30C
2.91
-
-
pH 8.5, 30C
2.91
-
-
pH 8.6, 30C
8.5
-
-, O13427
cell-free extract
41
-
O50584, -
pH 8.0, 30C
pH OPTIMUM
pH MAXIMUM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
7
8
-
recombinant enzyme
8
8.5
O50584, -
-
8
-
O50584, -
assay at
8
-
P37303
assay at
8
-
-, P75823
assay at
8
-
-
assay at
8.5
9
P37303
aldehyde formation from L-allo-threonine
8.5
9
-, P75823
-
8.5
-
-
assay at
8.5
-
-
substrate: L-threonine, Tris-chloride buffer
10
-
-
substrate: L-allo-threonine, Tris-chloride buffer
TEMPERATURE OPTIMUM
TEMPERATURE OPTIMUM MAXIMUM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
25
-
O50584, -
-
25
-
-
assay at
30
-
O50584, -
assay at
30
-
-
assay at
30
-
P37303
assay at
30
-
-, P75823
assay at
50
-
-
recombinant enzyme
55
-
P37303
aldehyde formation from L-allo-threonine
65
70
-, P75823
-
MOLECULAR WEIGHT
MOLECULAR WEIGHT MAXIMUM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
37000
-
-
subunit, SDS-PAGE
41810
-
-, O13427
calculated from amino acid sequence
140000
-
-, P75823
gel filtration
145000
-
O50584, -
gel filtration
150000
-
-
gel filtration
170000
-
P37303
gel filtration
277000
-
-
ultracentrifugation
SUBUNITS
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
homotetramer
P37303
4 * 41000, SDS-PAGE; 4 * 42000, calculated from sequence
homotetramer
-
4 * 37500, gel filtration
tetramer
O50584, -
4 * 38000, SDS-PAGE
tetramer
-, P75823
4 * 36500, SDS-PAGE
tetramer
-
4 * 38000, SDS-PAGE
-
Crystallization/COMMENTARY
ORGANISM
UNIPROT ACCESSION NO.
LITERATURE
pH STABILITY
pH STABILITY MAXIMUM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
5.5
9
O50584, -
30C, 30 min, stable
6
9.5
-, P75823
30C, 30 min, stable
6.5
10
P37303
30 min, stable
TEMPERATURE STABILITY
TEMPERATURE STABILITY MAXIMUM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
25
-
O50584, -
40C, 15 min, 50% loss of activity
50
-
P37303
15 min, enzyme retains only 25% of activity
60
-
-, P75823
1 h, stable
60
-
-
the residual L-TA activity after a heat treatment for 20 min at 60C is 10.6%
63
-
-
the half-life of the wild type L-TA at 63C is 1.3 min
Purification/COMMENTARY
ORGANISM
UNIPROT ACCESSION NO.
LITERATURE
-
-, P75823
-
O50584, -
Hiprep 16/10 DEAE FF column chromatography, Super Sepharose column chromatography, and HiLoad 16/10 Phenyl Sepharose HP column chromatography
-
Cloned/COMMENTARY
ORGANISM
UNIPROT ACCESSION NO.
LITERATURE
-
-, P75823
overexpression in Escherichia coli
O50584, -
cloned into pUCl18, and expressed in Escherichia coli
P37303
recombinantly expressed in Escherichia coli
-
expressed in Escherichia coli strain JM109
-
ENGINEERING
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
K207A
O50584, -
the mutant enzyme shows no detectable enzyme activity. The mutant enzyme show the disappearance of the absorption maximum at 420 nm, indicating that the Schiff base linkage between the epsilon-amino group of the active-site lysine residue and the pyridoxal 5'-phosphate cofactor aldehyde group of the wild type is not present in the mutant enzyme
K207R
O50584, -
the mutant enzyme shows a specific activity of about 1000 times lower than that of the wild-type enzyme. The mutant enzyme show the disappearance of the absorption maximum at 420 nm, indicating that the Schiff base linkage between the epsilon-amino group of the active-site lysine residue and the pyridoxal 5'-phosphate cofactor aldehyde group of the wild type is not present in the mutant enzyme
K207A
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the mutant enzyme shows no detectable enzyme activity. The mutant enzyme show the disappearance of the absorption maximum at 420 nm, indicating that the Schiff base linkage between the epsilon-amino group of the active-site lysine residue and the pyridoxal 5'-phosphate cofactor aldehyde group of the wild type is not present in the mutant enzyme
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K207R
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the mutant enzyme shows a specific activity of about 1000 times lower than that of the wild-type enzyme. The mutant enzyme show the disappearance of the absorption maximum at 420 nm, indicating that the Schiff base linkage between the epsilon-amino group of the active-site lysine residue and the pyridoxal 5'-phosphate cofactor aldehyde group of the wild type is not present in the mutant enzyme
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A169T
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stability-enhanced mutant, half life at 63C is 3.7 min
D104N
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stability-enhanced mutant, half life at 63C is 5.8 min
F18I
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stability-enhanced mutant, half life at 63C is 5.0 min, the specific activity is decreased by 45% compared to the wild type enzyme
H177Y
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stability-enhanced mutant, half life at 63C is 14.6 min
R241C/A287V
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the mutations dramatically increase the diastereoselectivity of the reverse aldol condensation activity for L-threo-3,4-dihydroxyphenylserine
V86I/R241C/Y306C
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the mutations dramatically increase the diastereoselectivity of the reverse aldol condensation activity for L-threo-3,4-dihydroxyphenylserine
Y34C
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the mutation dramatically increases the diastereoselectivity of the reverse aldol condensation activity for L-threo-3,4-dihydroxyphenylserine
Y39C/Y306C
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the mutations dramatically increase the diastereoselectivity of the reverse aldol condensation activity for L-threo-3,4-dihydroxyphenylserine
Y39C/Y306C/A48T
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the mutations dramatically increase the diastereoselectivity of the reverse aldol condensation activity for L-threo-3,4-dihydroxyphenylserine
Y39C/Y306C/R316C
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the mutations dramatically increase the diastereoselectivity of the reverse aldol condensation activity for L-threo-3,4-dihydroxyphenylserine
APPLICATION
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
biotechnology
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a continuous bioconversion system for L-threo-3,4-dihydroxyphenylserine production is developed that uses whole-cell biocatalyst of recombinant Escherichia coli expressing L-TA genes cloned from Streptomyces avelmitilis MA-4680. Maximum conversion rates are observed at 2 M glycine, 145 mM 3,4-dihydroxybenzaldehyde, 0.75% Triton-X, 5 g Escherichia coli cells/l, pH 6.5 and 10C. In the optimized condition, overall productivity is 8 g/l