Information on EC 4.2.3.1 - threonine synthase

New: Word Map on EC 4.2.3.1
Please wait a moment until all data is loaded. This message will disappear when all data is loaded.
Specify your search results
Mark a special word or phrase in this record:
Search Reference ID:
Select one or more organisms in this record:
Show additional data
Do not include text mining results
Include (text mining) results (more...)
Include results (AMENDA + additional results, but less precise; more...)


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

EC NUMBER
COMMENTARY hide
4.2.3.1
-
RECOMMENDED NAME
GeneOntology No.
threonine synthase
REACTION
REACTION DIAGRAM
COMMENTARY hide
ORGANISM
UNIPROT
LITERATURE
O-phospho-L-homoserine + H2O = L-threonine + phosphate
show the reaction diagram
REACTION TYPE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
elimination
PATHWAY
BRENDA Link
KEGG Link
MetaCyc Link
Biosynthesis of secondary metabolites
-
-
Glycine, serine and threonine metabolism
-
-
L-threonine biosynthesis
-
-
Metabolic pathways
-
-
Microbial metabolism in diverse environments
-
-
threonine metabolism
-
-
Vitamin B6 metabolism
-
-
SYSTEMATIC NAME
IUBMB Comments
O-phospho-L-homoserine phosphate-lyase (adding water; L-threonine-forming)
A pyridoxal-phosphate protein.
CAS REGISTRY NUMBER
COMMENTARY hide
9023-97-6
-
ORGANISM
COMMENTARY hide
LITERATURE
UNIPROT
SEQUENCE DB
SOURCE
-
-
-
Manually annotated by BRENDA team
var. altissima
-
-
Manually annotated by BRENDA team
wild type and several methionine-overproducing strains
-
-
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
SUBSTRATE
PRODUCT                       
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate) hide
LITERATURE
(Substrate)
COMMENTARY
(Product) hide
LITERATURE
(Product)
Reversibility
r=reversible
ir=irreversible
?=not specified
DL-3-chloroalanine
pyruvate + NH3 + HCl
show the reaction diagram
-
beta-elimination
-
ir
DL-vinylglycine + H2O
L-threonine
show the reaction diagram
-
-
-
ir
L-allo-threonine + H2O
2-oxobutyrate + NH3
show the reaction diagram
-
beta-elimination
-
ir
L-serine
pyruvate + NH3
show the reaction diagram
-
beta-elimination
-
ir
L-vinylglycine + phosphate + H2O
L-threonine + phosphate
show the reaction diagram
in the presence of phosphate, L-threonine is formed with kcat and reaction specificity comparable with those when O-phospho-L-homoserine is used as the substrate. In the absence of phosphate or when sulfate is used in place of phosphate, only the side reaction product, alpha-ketobutyrate, is formed. Compared with the more acidic sulfate ion, the phosphate ion decreases the energy levels of the transition states of the addition of water at the Cbeta of the PLP-alpha-aminocrotonate aldimine and the transaldimination to form L-threonine. Threonine synthase is in the closed form, when the substrate and the intermediates are bound to the enzyme
-
-
?
O-phospho-L-homoserine
?
show the reaction diagram
O-phospho-L-homoserine + H2O
L-threonine + phosphate
show the reaction diagram
phosphohomoserine
2-oxobutyrate + phosphate + ?
show the reaction diagram
-
bypass of threonine in isoleucine biosynthesis
-
ir
threonine
2-oxobutyrate + NH3
show the reaction diagram
additional information
?
-
NATURAL SUBSTRATES
NATURAL PRODUCTS
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate) hide
LITERATURE
(Substrate)
COMMENTARY
(Product) hide
LITERATURE
(Product)
REVERSIBILITY
r=reversible
ir=irreversible
?=not specified
O-phospho-L-homoserine
?
show the reaction diagram
O-phospho-L-homoserine + H2O
L-threonine + phosphate
show the reaction diagram
COFACTOR
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
pyridoxal 5'-phosphate
INHIBITORS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
AMP-derivatives
-
-
-
DL-2-amino-3[(phosphonomethyl)thio]propionic acid
-
Ki: 0.057 mM, kinact: 1.44 min-1
DL-E-2-amino-5-phosphono-4-pentenoic acid
-
Ki: 0.54 mM
GMP
-
25% inhibition at 67 mM
IMP
-
23% inhibition at 67 mM
KCN
-
22% inhibition at 1 mM
L-2,3-methanohomoserine phosphate
-
Ki: 0.01 mM
L-2-amino-3[(phosphonomethyl)thio]propionic acid
L-3-hydroxyhomoserine
-
Ki: 0.05 mM
L-cysteine
L-threo-3-hydroxyhomoserine
NH2OH
-
65% inhibition at 1 mM
O-phospho-DL-threonine
-
-
O-phospho-L-serine
-
-
phosphate
phospho-threonine
-
35% inhibition at 10 mM
phosphonovaleric acid
-
Ki: 0.031 mM
-
Vinylglycine
-
22% inhibition at 10 mM
ACTIVATING COMPOUND
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
S-adenosyl-L-methionine
S-adenosylmethionine
KM VALUE [mM]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
0.34 - 1.2
O-phospho-L-homoserine
0.03 - 2.7
O-phosphohomoserine
0.002 - 0.007
O-phospohomoserine
-
at saturating S-adenosylmethionine concentrations
TURNOVER NUMBER [1/s]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
0.61
L-Vinylglycine
Thermus thermophilus
Q5SL02
pH 8.0, 25C
0.8 - 4080
O-phospho-L-homoserine
0.0333 - 7.33
O-phosphohomoserine
0.034
phosphate
Thermus thermophilus
Q5SL02
pH 8.0, 25C
kcat/KM VALUE [1/mMs-1]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
0.0059
L-Vinylglycine
Thermus thermophilus
Q5SL02
pH 8.0, 25C
2204
5.2
O-phospho-L-homoserine
Thermus thermophilus
Q5SL02
pH 8.0, 25C
3655
0.0013
phosphate
Thermus thermophilus
Q5SL02
pH 8.0, 25C
16
Ki VALUE [mM]
INHIBITOR
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
0.057
DL-2-amino-3[(phosphonomethyl)thio]propionic acid
-
kinact: 1.44 min-1
0.54
DL-E-2-amino-5-phosphono-4-pentenoic acid
-
-
0.01
L-2,3-methanohomoserine phosphate
-
-
0.011
L-2-amino-3[(phosphonomethyl)thio]propionic acid
-
-
0.05
L-3-hydroxyhomoserine
-
-
0.006
L-threo-3-hydroxyhomoserine
-
-
0.031
phosphonovaleric acid
-
-
-
SPECIFIC ACTIVITY [µmol/min/mg]
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
0.00098 - 0.00246
-
purified enzyme from cloned gene
0.012
-
-
0.014
-
mutation Ile-3
0.018
-
wild type
7.7
-
purified enzyme from cloned gene
8.8
-
mutation SprA-44
additional information
pH OPTIMUM
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
7.8
-
enzyme assay at, recombinant enzyme
8.5
-
enyzme assay at
pH RANGE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
6.8 - 8.4
-
-
TEMPERATURE OPTIMUM
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
20
-
enzyme assay at
35
-
enzyme assay at
37
-
enzyme assay at, recombinant enzyme
pI VALUE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
6.6
-
calculated
SOURCE TISSUE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
SOURCE
LOCALIZATION
ORGANISM
UNIPROT
COMMENTARY hide
GeneOntology No.
LITERATURE
SOURCE
PDB
SCOP
CATH
ORGANISM
UNIPROT
Aquifex aeolicus (strain VF5)
Brucella melitensis biotype 1 (strain 16M / ATCC 23456 / NCTC 10094)
Burkholderia thailandensis (strain E264 / ATCC 700388 / DSM 13276 / CIP 106301)
Escherichia coli (strain K12)
Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv)
Saccharomyces cerevisiae (strain ATCC 204508 / S288c)
Thermus thermophilus (strain HB8 / ATCC 27634 / DSM 579)
Thermus thermophilus (strain HB8 / ATCC 27634 / DSM 579)
MOLECULAR WEIGHT
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
46000 - 48000
-
gel filtration
53000
-
gel filtration
110000
-
gel filtration
135000
-
gel filtration
190000
-
gel filtration
SUBUNITS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
?
-
x * 57200, calculated
homodimer
homotrimer
-
3 * 48000 (calculated 49100), SDS-PAGE, gelfiltration
monomer
-
1 * 52800, SDS-PAGE
additional information
Crystallization/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
crystallographic structure of Arabidopsis thaliana threonine synthase in complex with pyridoxal phosphate and with pyridoxal phosphate and S-adenosylmethionine; hanging drop method, 4C, pH 6.5, resolution of 2.6 A
-
hanging-drop vapour-diffusion method at 293 K. Selenomethionine-substituted apo threonine synthase, 14 Met residues in 58000 Da
-
hanging-drop vapour-diffusion method, crystal structure of apo threonine synthase as solved at 2.25 A resolution from triclinic crystals
-
x-ray diffraction studies
-
refined to 2.5 A. The structure of MtTS has a homodimeric organization in which the two subunits are related by a non-crystallographic 2fold axis. Each subunit is composed of three domains
sitting-drop vapour-diffusion method, crystal structure at 2.7 A resolution
-
apo-protein and in complex with 2-amino-5-phosphonopentanoic acid and with (E)-4-(3-hydroxy-2-methyl-5-(phosphonooxymethyl)pyridin-4-yl)-2-oxobut-3-enoic acid. The enzyme does not undergo any global conformational change upon the binding of pyridoxal 5'-phosphate. The binding of the substrate analog 2-amino-5-phosphonopentanoic acid to the holoenzyme induces a large conformational change from the open to the closed form in which the small domain moves as a rigid body to close the active site. This closed structure is maintained in the complex with (E)-4-(3-hydroxy-2-methyl-5-(phosphonooxymethyl)pyridin-4-yl)-2-oxobut-3-enoic acid, indicating that threonine synthase is in the closed form in the enamine and the pyridoxal 5'-phosphate-alpha-aminocrotonate aldimine intermediates
comparative QM/MM calculations. The base that abstracts a proton from the attacking water is the epsilon-amino group of Lys61 rather than the phosphate ion. The phosphate ion is important for stabilizing the transition state of the normal transaldimination to form L-threonine by making a hydrogen bond with the hydroxy group of the L-threonine moiety. Proposal of a mechanism, in which a proton temporarily resides at the phenolate O3' of pyridoxal-5'-phosphate, for the transaldimination process
-
hanging drop vapour diffusion method at 293 K, unligated enzyme form and complex with substrate analogue 2-amino-5-phosphonopentanoic acid, structure determined at 2.15 A and 2.0 A resolution
-
pH STABILITY
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
5.2
-
inactivation and precipitation below
137544
7
MtTS is inactivated at pH 7 or below
728848
TEMPERATURE STABILITY
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
60
MtTS loses less than 10% of the initial activity during a 10 min incubation
GENERAL STABILITY
ORGANISM
UNIPROT
LITERATURE
bovine serum albumine stabilizes
-
STORAGE STABILITY
ORGANISM
UNIPROT
LITERATURE
-15C, glycylglycine, several months
-
-80C, MOPS-buffer, pH 7.5, EDTA, dithioerythritol, 2-benzothiazolethiol, glycerol, polyvinylpyrrolidone, several months, no loss of activity
-
-80C, Na-HEPES buffer, pH 7.5, several months, no loss of activity
-
-80C, pH 7.8, several months
-
Purification/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
native and recombinant enzymes
-
Ni2+-affinity chromatography
-
partial
recombinant enzyme
-
using Ni-NTA chromatography
Cloned/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
expressed as a His-tagged fusion protein
expressed in Escherichia coli
expressed in Escherichia coli Gif41 (thrC mutant)
-
expressed in Nicotiana tabacum
-
expression in Escherichia coli
expression in transgenic Arabidopsis
-
His-tagged version expressed in Escherichia coli BL21(DE3)
-
overexpression under the control of the 35S cauliflower mosaic virus promotor in Arabidopsis sp. plants
-
ENGINEERING
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
additional information
APPLICATION
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
agriculture
analysis
-
continuous, coupled spectrophotometric threonine synthase assay. The sequential actions of threonine deaminase and hydroxyisocaproate dehydrogenase convert the L-Thr product of TS to alpha-ketobutyrate and then to 2-hydroxybutyrate, respectively, and are monitored as the decrease in absorbance at 340 nm resulting from the concomitant oxidation of beta-nicotinamide adenine dinucleotide to NAD+ by hydroxyisocaproate dehydrogenase
medicine
nutrition
-
interesting with respect to attempts to obtain transgenic plants with elevated levels of essential amino acids Met, Lys, Thr
Show AA Sequence (7613 entries)
Longer loading times are possible. Please use the Sequence Search for a certain query.