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
LITERATURE
L-allo-threonine = glycine + acetaldehyde
show the reaction diagram
-
-
-
-
L-threonine = glycine + acetaldehyde
show the reaction diagram
(1)
-
-
-
PATHWAY
BRENDA Link
KEGG Link
MetaCyc Link
glycine biosynthesis IV
-
-
L-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
COMMENTARY
LITERATURE
LtaE
-
-
-
-
ORGANISM
COMMENTARY
LITERATURE
UNIPROT
SEQUENCE DB
SOURCE
strain SGY269
SwissProt
Manually annotated by BRENDA team
Candida albicans SGY269
strain SGY269
SwissProt
Manually annotated by BRENDA team
Caulobacter vibrioides CB15
-
UniProt
Manually annotated by BRENDA team
serine hydroxymethyl transferase with threonine aldolase activity; MG1655
Uniprot
Manually annotated by BRENDA team
GENERAL INFORMATION
ORGANISM
UNIPROT
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
-
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
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
SUBSTRATE
PRODUCT                      
REACTION DIAGRAM
ORGANISM
UNIPROT
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-(3-methylsulfonylphenyl)serine
glycine + 3-methylsulfonylbenzaldehyde
show the reaction diagram
P0A825
121% of the activity with L-threonine
-
-
?
DL-threo-(3-nitrophenyl)serine
glycine + 3-nitrobenzaldehyde
show the reaction diagram
P0A825
143% of the activity with L-threonine
-
-
?
DL-threo-phenylserine
glycine + benzaldehyde
show the reaction diagram
P75823
-
-
-
?
DL-threo-phenylserine
glycine + benzaldehyde
show the reaction diagram
P0A825
180% of the activity with L-threonine
-
-
?
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
Q9A3V8
-
-
-
?
L-allo-threonine
glycine + acetaldehyde
show the reaction diagram
E7U392
-
-
-
?
L-allo-threonine
glycine + acetaldehyde
show the reaction diagram
P0A825
291% of the activity with L-threonine
-
-
?
L-allo-threonine
glycine + acetaldehyde
show the reaction diagram
Caulobacter vibrioides CB15
Q9A3V8
-
-
-
?
L-allo-threonine
glycine + acetaldehyde
show the reaction diagram
E7U392
-
-
-
?
L-allo-threonine
glycine + acetaldehyde
show the reaction diagram
O50584
-
-
-
r
L-erythro-phenylserine
glycine + benzaldehyde
show the reaction diagram
O50584
-
-
-
?
L-serine
glycine + formaldehyde
show the reaction diagram
-
-
-
-
?
L-Thr
Gly + acetaldehyde
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-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
P0A825
-
-
-
?
L-threonine
glycine + acetaldehyde
show the reaction diagram
Q9A3V8
-
-
-
?
L-threonine
glycine + acetaldehyde
show the reaction diagram
E7U392
-
-
-
?
L-threonine
glycine + acetaldehyde
show the reaction diagram
Caulobacter vibrioides CB15
Q9A3V8
-
-
-
?
L-threonine
glycine + acetaldehyde
show the reaction diagram
Candida albicans SGY269
O13427
-
-
r
L-threonine
glycine + acetaldehyde
show the reaction diagram
E7U392
-
-
-
?
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
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
?
-
Candida albicans, Candida albicans SGY269
O13427
glycine metabolism
-
?
COFACTOR
ORGANISM
UNIPROT
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
COMMENTARY
LITERATURE
K+
-
K+ or NH4+ required for maximal activity
INHIBITORS
ORGANISM
UNIPROT
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
COMMENTARY
LITERATURE
IMAGE
NH4+
-
K+ or NH4+ required for maximal activity
sodium sulfite
A0T1V9
addition of sodium sulfite stimulates the production of L-threo-3,4-dihydroxyphenylserine without affecting the diastereoselectivity ratio, especially at 50 mM
Triton X-100
A0T1V9
highest conversion yield at a 0.75% without affecting the diastereoselectivity ratio
KM VALUE [mM]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
0.24
DL-erythro-phenylserine
P75823
pH 8.0, 30C
23.6
DL-threo-(3-methylsulfonylphenyl)serine
P0A825
pH 7.0, 37C
-
21.5
DL-threo-(3-nitrophenyl)serine
P0A825
pH 7.0, 37C
-
0.12
DL-threo-phenylserine
P75823
pH 8.0, 30C
19.2
DL-threo-phenylserine
P0A825
pH 7.0, 37C
0.027
L-4-hydroxythreonine
-
pH 8.0, 25C
0.052
L-allo-threonine
-
pH 8.0, 25C
0.2
L-allo-threonine
E7U392
mutant H126NF, pH 7.0, 30C
0.22
L-allo-threonine
P75823
pH 8.0, 30C
0.24
L-allo-threonine
E7U392
wild-type, pH 7.0, 30C
0.69
L-allo-threonine
Q9A3V8
wild-type, pH 8.0, 30C
0.96
L-allo-threonine
E7U392
mutant H126N, pH 7.0, 30C
1 - 2
L-allo-threonine
Q9A3V8
mutant D95L, pH 8.0, 30C
1.3
L-allo-threonine
E7U392
mutant F87A, pH 7.0, 30C
1.5
L-allo-threonine
P0A825
pH 7.0, 37C
1.7
L-allo-threonine
E7U392
mutant F87D, pH 7.0, 30C; mutant H83N, pH 7.0, 30C
2.5
L-allo-threonine
Q9A3V8
mutant D95W, pH 8.0, 30C
2.7
L-allo-threonine
Q9A3V8
mutant D95Y, pH 8.0, 30C
2.9
L-allo-threonine
Q9A3V8
mutant D95G/E96G, pH 8.0, 30C
4.4
L-allo-threonine
Q9A3V8
mutant D95Y/E96T, pH 8.0, 30C
5
L-allo-threonine
E7U392
mutant K222A, pH 7.0, 30C
7
L-allo-threonine
E7U392
mutant H83F, pH 7.0, 30C
7.1
L-allo-threonine
Q9A3V8
mutant D95N/E96S, pH 8.0, 30C
10
L-allo-threonine
P37303
pH 8.0, 30C
11
L-allo-threonine
Q9A3V8
mutant D95C, pH 8.0, 30C
14.6
L-allo-threonine
O50584
pH 8.0, 30C
31
L-allo-threonine
E7U392
mutant H83F/H126F, pH 7.0, 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
0.4
L-threonine
E7U392
mutant F87A, pH 7.0, 30C
1 - 3
L-threonine
Q9A3V8
mutant D95G/E96G, pH 8.0, 30C
1.1
L-threonine
E7U392
mutant H83F/H126F, pH 7.0, 30C
1.3
L-threonine
E7U392
mutant F87D, pH 7.0, 30C
1.7
L-threonine
E7U392
mutant H126F, pH 7.0, 30C
2.85
L-threonine
P75823
pH 8.0, 30C
3.7
L-threonine
E7U392
mutant K222A, pH 7.0, 30C
4
L-threonine
-
pH 8.0, 25C
7
L-threonine
E7U392
mutant H83F, pH 7.0, 30C
13.6
L-threonine
Q9A3V8
wild-type, pH 8.0, 30C
14.7
L-threonine
O50584
pH 8.0, 30C
19.4
L-threonine
E7U392
wild-type, pH 7.0, 30C
32
L-threonine
Q9A3V8
mutant D95N/E96S, pH 8.0, 30C
38
L-threonine
E7U392
mutant H83N, pH 7.0, 30C
43.1
L-threonine
P0A825
pH 7.0, 37C
44
L-threonine
Q9A3V8
mutant D95C, pH 8.0, 30C; mutant D95W, pH 8.0, 30C
50
L-threonine
Q9A3V8
mutant D95M, pH 8.0, 30C
53
L-threonine
Q9A3V8
mutant D95L, pH 8.0, 30C
55
L-threonine
P37303
pH 8.0, 30C
61
L-threonine
E7U392
mutant H126N, pH 7.0, 30C
63
L-threonine
Q9A3V8
mutant D95Y, pH 8.0, 30C
TURNOVER NUMBER [1/s]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
1.44
L-4-hydroxythreonine
-
pH 8.0, 25C
0.06
L-allo-threonine
E7U392
mutant H83F, pH 7.0, 30C
0.2
L-allo-threonine
Q9A3V8
mutant D95N/E96S, pH 8.0, 30C
1.28
L-allo-threonine
E7U392
mutant H83N, pH 7.0, 30C
3
L-allo-threonine
Q9A3V8
mutant D95Y/E96T, pH 8.0, 30C
3.2
L-allo-threonine
-
pH 8.0, 25C
3.55
L-allo-threonine
E7U392
wild-type, pH 7.0, 30C
7.82
L-allo-threonine
E7U392
mutant H126N, pH 7.0, 30C
8.6
L-allo-threonine
Q9A3V8
mutant D95G/E96G, pH 8.0, 30C
9.02
L-allo-threonine
E7U392
mutant H126NF, pH 7.0, 30C
19
L-allo-threonine
Q9A3V8
mutant D95C, pH 8.0, 30C; mutant D95W, pH 8.0, 30C
20
L-allo-threonine
Q9A3V8
mutant D95Y, pH 8.0, 30C; wild-type, pH 8.0, 30C
22
L-allo-threonine
Q9A3V8
mutant D95L, pH 8.0, 30C
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)
0.02
L-threonine
E7U392
mutant H83F, pH 7.0, 30C
0.2
L-threonine
Q9A3V8
mutant D95N/E96S, pH 8.0, 30C
0.28
L-threonine
E7U392
mutant H83N, pH 7.0, 30C
0.6
L-threonine
Q9A3V8
mutant D95G/E96G, pH 8.0, 30C
1.1
L-threonine
-
pH 8.0, 25C
1.87
L-threonine
E7U392
wild-type, pH 7.0, 30C
3
L-threonine
Q9A3V8
mutant D95C, pH 8.0, 30C
3.3
L-threonine
Q9A3V8
wild-type, pH 8.0, 30C
3.5
L-threonine
Q9A3V8
mutant D95Y, pH 8.0, 30C
3.6
L-threonine
Q9A3V8
mutant D95M, pH 8.0, 30C
3.8
L-threonine
Q9A3V8
mutant D95L, pH 8.0, 30C
4.37
L-threonine
E7U392
mutant H126N, pH 7.0, 30C
6
L-threonine
E7U392
mutant H126F, pH 7.0, 30C
9.6
L-threonine
Q9A3V8
mutant D95W, pH 8.0, 30C
43
L-threonine
P37303
pH 8.0, 30C
kcat/KM VALUE [1/mMs-1]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
5.3
L-4-hydroxythreonine
-
pH 8.0, 25C
28479
0.01
L-allo-threonine
E7U392
mutant H83F, pH 7.0, 30C
2967
0.028
L-allo-threonine
Q9A3V8
mutant D95N/E96S, pH 8.0, 30C
2967
0.68
L-allo-threonine
Q9A3V8
mutant D95Y/E96T, pH 8.0, 30C
2967
0.75
L-allo-threonine
E7U392
mutant H83N, pH 7.0, 30C
2967
1.7
L-allo-threonine
Q9A3V8
mutant D95C, pH 8.0, 30C
2967
1.8
L-allo-threonine
Q9A3V8
mutant D95L, pH 8.0, 30C
2967
3
L-allo-threonine
Q9A3V8
mutant D95G/E96G, pH 8.0, 30C
2967
4.1
L-allo-threonine
P37303
pH 8.0, 30C
2967
6.2
L-allo-threonine
-
pH 8.0, 25C
2967
7.4
L-allo-threonine
Q9A3V8
mutant D95Y, pH 8.0, 30C
2967
7.6
L-allo-threonine
Q9A3V8
mutant D95W, pH 8.0, 30C
2967
8.13
L-allo-threonine
E7U392
mutant H126N, pH 7.0, 30C
2967
14.78
L-allo-threonine
E7U392
wild-type, pH 7.0, 30C
2967
29
L-allo-threonine
Q9A3V8
wild-type, pH 8.0, 30C
2967
45.08
L-allo-threonine
E7U392
mutant H126NF, pH 7.0, 30C
2967
0.0016
L-threonine
Q9A3V8
mutant D95Y/E96T, pH 8.0, 30C
250
0.0063
L-threonine
Q9A3V8
mutant D95N/E96S, pH 8.0, 30C
250
0.01
L-threonine
E7U392
mutant H83N, pH 7.0, 30C
250
0.046
L-threonine
Q9A3V8
mutant D95G/E96G, pH 8.0, 30C
250
0.056
L-threonine
Q9A3V8
mutant D95Y, pH 8.0, 30C
250
0.068
L-threonine
Q9A3V8
mutant D95C, pH 8.0, 30C
250
0.07
L-threonine
E7U392
mutant H126N, pH 7.0, 30C
250
0.072
L-threonine
Q9A3V8
mutant D95L, pH 8.0, 30C; mutant D95M, pH 8.0, 30C
250
0.1
L-threonine
E7U392
wild-type, pH 7.0, 30C
250
0.218
L-threonine
Q9A3V8
mutant D95W, pH 8.0, 30C
250
0.24
L-threonine
Q9A3V8
wild-type, pH 8.0, 30C
250
0.78
L-threonine
P37303
pH 8.0, 30C
250
2.8
L-threonine
-
pH 8.0, 25C
250
3.53
L-threonine
E7U392
mutant H126F, pH 7.0, 30C
250
SPECIFIC ACTIVITY [µmol/min/mg]
ORGANISM
UNIPROT
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
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
7 - 8
-
recombinant enzyme
8 - 8.5
O50584
-
8
O50584
assay at
8
P37303
assay at
8
P75823
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
ORGANISM
UNIPROT
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
-
PDB
SCOP
CATH
ORGANISM
Escherichia coli (strain K12)
MOLECULAR WEIGHT
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
37000
-
subunit, SDS-PAGE
681356
41810
O13427
calculated from amino acid sequence
654020
140000
P75823
gel filtration
5206
145000
O50584
gel filtration
441433
150000
-
gel filtration
681356
170000
P37303
gel filtration
5205
277000
-
ultracentrifugation
5195, 5198
SUBUNITS
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
homotetramer
P37303
4 * 41000, SDS-PAGE
homotetramer
-
4 * 37500, gel filtration
homotetramer
P37303
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
LITERATURE
at 2.2 A resolution, in the unliganded form and cocrystallized with L-serine and L-threonine. No active site catalytic residue is revealed, and a structural water molecule is assumed to act as the catalytic base in the retro-aldol cleavage reaction. The very large active site opening suggests that much larger molecules than L-threonine isomers may be easily accommodated
E7U392
pH STABILITY
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
5.5 - 9
O50584
30C, 30 min, stable
441433
6 - 9.5
P75823
30C, 30 min, stable
5206
6.5 - 10
P37303
30 min, stable
5205
TEMPERATURE STABILITY
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
25
O50584
40C, 15 min, 50% loss of activity
441433
50
P37303
15 min, enzyme retains only 25% of activity
5205
60
P75823
1 h, stable
5206
60
-
the residual L-TA activity after a heat treatment for 20 min at 60C is 10.6%
681356
63
-
the half-life of the wild type L-TA at 63C is 1.3 min
681356
Purification/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
Hiprep 16/10 DEAE FF column chromatography, Super Sepharose column chromatography, and HiLoad 16/10 Phenyl Sepharose HP column chromatography
-
Cloned/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
expression in Escherichia coli
E7U392
overexpression in Escherichia coli
O50584
cloned into pUCl18, and expressed in Escherichia coli
P37303
expression in Escherichia coli
A0T1V9
recombinantly expressed in Escherichia coli
-
expressed in Escherichia coli strain JM109
-
ENGINEERING
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
D176E
Q9A3V8
500fold decrease in catalytic efficiency
D95C
Q9A3V8
less than 10% of catalytic efficiency of wild-type
D95H/E96G
Q9A3V8
less than 10% of catalytic efficiency of wild-type
D95L
Q9A3V8
less than 10% of catalytic efficiency of wild-type
D95M
Q9A3V8
less than 5% of catalytic efficiency of wild-type
D95N/E96S
Q9A3V8
less than 5% of catalytic efficiency of wild-type
D95W
Q9A3V8
less than 2% of catalytic efficiency of wild-type
D95Y
Q9A3V8
less than 5% of catalytic efficiency of wild-type
D95Y/E96T
Q9A3V8
less than 10% of catalytic efficiency of wild-type
D176E
Caulobacter vibrioides CB15
-
500fold decrease in catalytic efficiency
-
D95C
Caulobacter vibrioides CB15
-
less than 10% of catalytic efficiency of wild-type
-
D95L
Caulobacter vibrioides CB15
-
less than 10% of catalytic efficiency of wild-type
-
D95M
Caulobacter vibrioides CB15
-
less than 5% of catalytic efficiency of wild-type
-
D95Y
Caulobacter vibrioides CB15
-
less than 5% of catalytic efficiency of wild-type
-
F87A
E7U392
no change in the ration of cleavage of L-threonine to L-allo-threonine
F87D
E7U392
mutation doubles the preference of the enzyme for L-allo-threonine
H126F
E7U392
300% of wild-type activity,reduced preference for the erythro-substrate
H126N
E7U392
60% of wild-type activity
H83F
E7U392
less than 1% of wild-type activity, reduced preference for the erythro-substrate
H83F/H126F
E7U392
able to catalyze the cleavage of both L-threonine and L-allo-threonine at a measurable rate, neither of the histidines acts as a catalytic base in the retro-aldol cleavage mechanism
H83N
E7U392
less than 10% of wild-type activity
K222A
E7U392
slight decrease in kcat and slight increase in Km values for both L-threonine and L-allo-threonine
F87A
-
no change in the ration of cleavage of L-threonine to L-allo-threonine
-
F87D
-
mutation doubles the preference of the enzyme for L-allo-threonine
-
H126F
-
300% of wild-type activity,reduced preference for the erythro-substrate
-
H126N
-
60% of wild-type activity
-
K222A
-
slight decrease in kcat and slight increase in Km values for both L-threonine and L-allo-threonine
-
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
-
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
-
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
-
A169T
-
stability-enhanced mutant, half life at 63C is 3.7 min
D104N
-
stability-enhanced mutant, half life at 63C is 5.8 min
F18I
-
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
-
stability-enhanced mutant, half life at 63C is 14.6 min
R241C/A287V
-
the mutations dramatically increase the diastereoselectivity of the reverse aldol condensation activity for L-threo-3,4-dihydroxyphenylserine
V86I/R241C/Y306C
-
the mutations dramatically increase the diastereoselectivity of the reverse aldol condensation activity for L-threo-3,4-dihydroxyphenylserine
Y34C
-
the mutation dramatically increases the diastereoselectivity of the reverse aldol condensation activity for L-threo-3,4-dihydroxyphenylserine
Y39C/Y306C
-
the mutations dramatically increase the diastereoselectivity of the reverse aldol condensation activity for L-threo-3,4-dihydroxyphenylserine
Y39C/Y306C/A48T
-
the mutations dramatically increase the diastereoselectivity of the reverse aldol condensation activity for L-threo-3,4-dihydroxyphenylserine
Y39C/Y306C/R316C
-
the mutations dramatically increase the diastereoselectivity of the reverse aldol condensation activity for L-threo-3,4-dihydroxyphenylserine
A169T
-
stability-enhanced mutant, half life at 63C is 3.7 min
-
D104N
-
stability-enhanced mutant, half life at 63C is 5.8 min
-
F18I
-
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
-
stability-enhanced mutant, half life at 63C is 14.6 min
-
R241C/A287V
-
the mutations dramatically increase the diastereoselectivity of the reverse aldol condensation activity for L-threo-3,4-dihydroxyphenylserine
-
V86I/R241C/Y306C
-
the mutations dramatically increase the diastereoselectivity of the reverse aldol condensation activity for L-threo-3,4-dihydroxyphenylserine
-
Y34C
-
the mutation dramatically increases the diastereoselectivity of the reverse aldol condensation activity for L-threo-3,4-dihydroxyphenylserine
-
Y39C/Y306C
-
the mutations dramatically increase the diastereoselectivity of the reverse aldol condensation activity for L-threo-3,4-dihydroxyphenylserine
-
Y39C/Y306C/A48T
-
the mutations dramatically increase the diastereoselectivity of the reverse aldol condensation activity for L-threo-3,4-dihydroxyphenylserine
-
APPLICATION
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
synthesis
P0A825
synthesis of optically active beta-hydroxy-alpha-amino acids by immobilized Escherichia coli cells expressing the enzyme. The immobilized cells can be continuously used 10 times, yielding an average conversion rate of 60.4%
synthesis
A0T1V9
production of L-threo-3,4-dihydroxyphenylserine. At the optimized conditions, a mixture of L-threo-3,4-dihydroxyphenylserine and L-erythro-3,4-dihydroxyphenylserine is synthesized by diastereoselectivity-enhanced L-threonine aldolase expressed in Escherichia coli in a continuous process for 100 h, yielding an average of 4.0 mg/ml of L-threo-3,4-dihydroxyphenylserine and 60% diastereoselectivity
biotechnology
-
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