Information on EC 2.4.1.123 - inositol 3-alpha-galactosyltransferase

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The enzyme appears in viruses and cellular organisms

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EC NUMBER
COMMENTARY hide
2.4.1.123
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RECOMMENDED NAME
GeneOntology No.
inositol 3-alpha-galactosyltransferase
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REACTION
REACTION DIAGRAM
COMMENTARY hide
ORGANISM
UNIPROT
LITERATURE
UDP-alpha-D-galactose + myo-inositol = UDP + O-alpha-D-galactosyl-(1->3)-1D-myo-inositol
show the reaction diagram
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-
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REACTION TYPE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
hexosyl group transfer
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PATHWAY
BRENDA Link
KEGG Link
MetaCyc Link
lychnose and isolychnose biosynthesis
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stachyose biosynthesis
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stellariose and mediose biosynthesis
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Galactose metabolism
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SYSTEMATIC NAME
IUBMB Comments
UDP-galactose:myo-inositol 3-alpha-D-galactosyltransferase
An enzyme from plants involved in the formation of raffinose and stachyose [cf. EC 2.4.1.67 (galactinol---raffinose galactosyltransferase) and EC 2.4.1.82 (galactinol---sucrose galactosyltransferase)].
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CAS REGISTRY NUMBER
COMMENTARY hide
79955-89-8
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ORGANISM
COMMENTARY hide
LITERATURE
UNIPROT
SEQUENCE DB
SOURCE
var. desi and kabuli
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Manually annotated by BRENDA team
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SwissProt
Manually annotated by BRENDA team
var. Black Beauty
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Manually annotated by BRENDA team
gene TsGOLS2
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Manually annotated by BRENDA team
3 low phytic mutants
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Manually annotated by BRENDA team
i.e. M. falcata, cv. Hulunbeir, gene MfGolS1
UniProt
Manually annotated by BRENDA team
cv. WL-525HQ, gene MsGolS1
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Manually annotated by BRENDA team
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UniProt
Manually annotated by BRENDA team
var. Big Red
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Manually annotated by BRENDA team
7 genotypes
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Manually annotated by BRENDA team
tomato, cv. Moneymaker, full length cDNA of LeGOLS-1; tomato, cv. Moneymaker, genomic sequence of LeGOLS-1
SwissProt
Manually annotated by BRENDA team
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-
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Manually annotated by BRENDA team
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SwissProt
Manually annotated by BRENDA team
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GENERAL INFORMATION
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
metabolism
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the enzyme is involved in the biosynthesis of raffinose family oligosaccharides catalyzing the first committed step
physiological function
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SUBSTRATE
PRODUCT                       
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate) hide
LITERATURE
(Substrate)
COMMENTARY
(Product) hide
LITERATURE
(Product)
Reversibility
r=reversible
ir=irreversible
?=not specified
UDP-alpha-D-galactose + myo-inositol
UDP + O-alpha-D-galactosyl-(1->3)-1D-myo-inositol
show the reaction diagram
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-
-
-
?
UDP-D-galactose + myo-inositol
UDP + alpha-D-galactosyl-(1-3)-1D-myo-inositol
show the reaction diagram
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i.e. galactinol
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?
UDP-galactose + myo-inositol
UDP + 1-O-alpha-D-galactosyl-D-myo-inositol
show the reaction diagram
UDP-galactose + myo-inositol
UDP + alpha-D-galactosyl-(1-3)-1D-myo-inositol
show the reaction diagram
UDP-galactose + myo-inositol
UDP + O-alpha-D-galactosyl-(1-3)-1D-myo-inositol
show the reaction diagram
additional information
?
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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
UDP-alpha-D-galactose + myo-inositol
UDP + O-alpha-D-galactosyl-(1->3)-1D-myo-inositol
show the reaction diagram
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-
-
-
?
UDP-D-galactose + myo-inositol
UDP + alpha-D-galactosyl-(1-3)-1D-myo-inositol
show the reaction diagram
Q84V66
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i.e. galactinol
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?
UDP-galactose + myo-inositol
UDP + 1-O-alpha-D-galactosyl-D-myo-inositol
show the reaction diagram
UDP-galactose + myo-inositol
UDP + alpha-D-galactosyl-(1-3)-1D-myo-inositol
show the reaction diagram
UDP-galactose + myo-inositol
UDP + O-alpha-D-galactosyl-(1-3)-1D-myo-inositol
show the reaction diagram
additional information
?
-
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METALS and IONS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
MnCl2
5 mM are included in assay medium
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INHIBITORS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
UDP
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product inhibition, 70% inhibition at 5 mM
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ACTIVATING COMPOUND
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
dithiothreitol
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absolute requirement
additional information
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KM VALUE [mM]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
4.5
myo-inositol
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0.4
UDP-galactose
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SPECIFIC ACTIVITY [µmol/min/mg]
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
0.00114
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protoplast
0.02826
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protoplast
3.8
purified BhGolS1-GST fusion protein is able to catalyze galactinol synthesis, 50 mM Hepes buffer, pH 7.0, 2 mM dithiothreitol, 5 mM MnCl2 and 0.5-1 mg purified enzyme protein
additional information
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pH OPTIMUM
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
5.5
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at 7 mM Mn2+
5.6
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assay at
6.2
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at 2 mM Mn2+
7
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at 0.2 mM Mn2+, broad activity optimum centered around pH 7
additional information
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Mn2+-concentration influences pH-optimum
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pH RANGE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
5 - 7
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about half-maximal activity at pH 5 and 7, at 7 mM Mn2+
5.1 - 7.8
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about half-maximal activity at pH 5.1 and 7.8, at 2.0 mM Mn2+
5.2 - 8.6
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about half-maximal activity at pH 5.2 and 8.6, at 0.2 mM Mn2+
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TEMPERATURE OPTIMUM
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
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SOURCE TISSUE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
SOURCE
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highest activity among all of the components of seed, much poorer source than Cucurbita pepo mature leaves
Manually annotated by BRENDA team
LeGOLS-1 mRNA is present in endosperm caps
Manually annotated by BRENDA team
GolS-2 is primarily expressed in the phloem-associated intermediary cells known for their role in raffinose family oligosaccharides phloem loading
Manually annotated by BRENDA team
LeGOLS-1 mRNA is most abundant in radicle tips
Manually annotated by BRENDA team
additional information
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LOCALIZATION
ORGANISM
UNIPROT
COMMENTARY hide
GeneOntology No.
LITERATURE
SOURCE
additional information
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not in lysates of chloroplasts from leaves
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Manually annotated by BRENDA team
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MOLECULAR WEIGHT
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
36000
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x * 36000, SDS-PAGE
38000
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x * 38000, SDS-PAGE
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SUBUNITS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
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POSTTRANSLATIONAL MODIFICATION
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
no modification
no putative serine phosphorylation site; no putative serine phosphorylation site
phosphoprotein
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TEMPERATURE STABILITY
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
40
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2 h, 50% loss of activity
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GENERAL STABILITY
ORGANISM
UNIPROT
LITERATURE
70-80% loss of activity during purification
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ammonium sulfate fractionation causes 32% loss of enzyme activity
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bovine serum albumin is essential to preserve enzyme activity during the assay
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STORAGE STABILITY
ORGANISM
UNIPROT
LITERATURE
-20°C, enzyme in ammonium sulfate precipitate form, 6-8 weeks, stable
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Purification/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
1591fold, copurified with a 41 and 43 kDa peptide
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2472fold
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partial, 41fold
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partially from leaves, by ammonium sulfate fractionation and anion exchange chromatography
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purification of glutathione S-transferase fusion proteins GTS-AtGolS1, 2 and 3, overexpressed in Escherichia coli; purification of glutathione S-transferase fusion proteins GTS-AtGolS1, 2 and 3, overexpressed in Escherichia coli; purification of glutathione S-transferase fusion proteins GTS-AtGolS1, 2 and 3, overexpressed in Escherichia coli
the soluble protein is separated by SDS-PAGE to check the molecular weight of the recombinant protein, which is then purified using Glutathione Sepharose TM 4B
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Cloned/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
7 AtGolS genes, cloning of AtGolS1, 2 and 3, AtGolS1 and 2 are induced by drought and high-salinity stresses, but not by cold stress, AtGolS3 is induced by cold stress, but not by drought or salt stress, overexpression of glutathione S-transferase fusion proteins GTS-AtGolS1, 2 and 3 in Escherichia coli, overexpression of AtGolS2 in transgenic Arabidopsis improves drought tolerance, AtGolS3 is controlled by the transcription factor DREB1A; 7 AtGolS genes, cloning of AtGolS1, 2 and 3, AtGolS1 and 2 are induced by drought and high-salinity stresses, but not by cold stress, AtGolS3 is induced by cold stress, but not by drought or salt stress, overexpression of glutathione S-transferase fusion proteins GTS-AtGolS1, 2 and 3 in Escherichia coli, overexpression of AtGolS2 in transgenic Arabidopsis improves drought tolerance, AtGolS3 is controlled by the transcription factor DREB1A; 7 AtGolS genes, cloning of AtGolS1, 2 and 3, AtGolS1 and 2 are induced by drought and high-salinity stresses, but not by cold stress, AtGolS3 is induced by cold stress, but not by drought or salt stress, overexpression of glutathione S-transferase fusion proteins GTS-AtGolS1, 2 and 3 in Escherichia coli, overexpression of AtGolS2 in transgenic Arabidopsis improves drought tolerance, AtGolS3 is controlled by the transcription factor DREB1A
coding region of BhGolS1 is inframe cloned into pGEX-4T-1 downstream to GST coding region and transformed into Escherichia coli BL21(DE3) and BL21 codon plus cells, generation of transgenic tobacco plants, constructs are introduced into Agrobacterium strain LBA4404 by electroporation and transformed into tobacco via a leaf disc method
cold-inducible GolS-1 and -2 genes encode 2 distinct galactinol synthases, cloning and sequencing of the GolS-1 and -2 genes, deduced amino acid sequences, expression of GolS-1 cDNA in Escherichia coli as functional enzyme; cold-inducible GolS-1 and -2 genes encode 2 distinct galactinol synthases, cloning and sequencing of the GolS-1 and -2 genes, deduced amino acid sequences, expression of GolS-1 cDNA in Escherichia coli as functional enzyme
desi and kabuli chickpea genotypes
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enzyme DNA as cloned into the predigested binary vector, tobacco is transformed by the leaf-disk method using Agrobacterium tumefaciens LBA4404 containing the CsGolS1 recombinant plasmid
expression in Escherichia coli
expression in Schizosaccharomyces pombe
gene MfGolS1, cloned from the cold-treated leaves by reverse transcription PCR, DNA and amino acid sequence determination and analysis, sequence comparisons and phylogenetic analysis, quantitative real-time quantitative PCR enzyme expression analysis, recombinant overexpression in Nicotiana tabacum cv. Zhongyan 90 seeds. Overexpression of MfGolS1 in tobacco results in elevated tolerance to freezing and chilling in transgenic plants as a result of enhanced levels of galactinol, raffinose and stachyose. Tolerance to drought and salt stresses is also increased in the transgenic tobacco plants
gene MsGolS1, sequence comparisons and phylogenetic analysis, quantitative real-time quantitative PCR enzyme expression analysis
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gene TsGOLS2, overexpression in Arabidopsis thaliana. The contents of galactinol, raffinose, and 2-oxoglutaric acid are significantly increased in transgenic plants compared to wild-type plants, and salt-stressed transgenic Arabidopsis thaliana plants exhibits higher germination rate, photosynthesis ability, and seedling growth. After being treated with osmotic stress by high concentration of sorbitol, transgenic plants retain high germination rates and grow well during early development
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LeGOLS-1 gene encoding a 318-amino acids peptide is cloned, gene and cDNA structure, LeGOLS-1 expression pattern in seeds and seedlings during seed maturation and germination under various conditions, hormonal control of transcription of LeGOLS-1 in the absence of gibberellin and abscisic acid, up-regulation of gene expression before maturation desiccation and again after imbibition whenever radicle protrusion is prevented
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EXPRESSION
ORGANISM
UNIPROT
LITERATURE
a WRKY transcription factor participates in dehydration tolerance in Boea hygrometrica by binding to the W-box elements of the galactinol synthase promoter, GolS genes are induced by a variety of stresses in both stress-sensitive and tolerant-plant species, mRNA and protein accumulate in leaves dehydrated for 2-48 h, and disappear after rehydration, BhGolS1 is rapidly induced by abscisic acid at the mRNA level after 0.5 h and at the protein level after 8 h
at 3 to 5 days after inoculation with Botrytis cinerea, the CsGolS1 overexpressors show more resistance to the pathogen infection (40 to 63% increase in the survival rate) compared with wild-type plants, expression of a galactinol synthase gene is primed in the leaves of cucumber plants by Pseudomonaschlororaphis O6 root colonization, the transcript of the Cucumis sativus induced systemic resistance gene 3 (CsISR3) clone, encoding a cucumber galactinol synthase is accumulated after a challenge inoculation with Corynespora cassiicola
gene expression of Os07g0687900 encoding galactinol synthase is upregulated by overexpression of the transcription factor 11 (WRKY11) induced by heat pretreatment
overexpression of the CsGolS1 gene confers resistance in transgenic tobacco plants against fungal and bacterial pathogens, the CsGolS1-overexpressing transgenic plants demonstrate constitutive resistance against the pathogens Botrytis cinerea and Erwinia carotovora, and they show an increased accumulation in galactinol content, the CsGolS1-overexpressing transgenic plants demonstrate an increased tolerance to drought and high salinity stresses
the enzyme is greatly induced in leaves, but not in stem and petiole, after cold treatment. MfGolS1 can be induced by myo-inositol, which is proposed to participate in cold-induced MfGolS1 expression. MfGolS1 transcript is weakly induced by dehydration and salt stresses, but not responsive to abscisic acid
the enzyme is slightly and short-time induced by cold treatment with low levels of accumulation of sugars including sucrose, galactinol, raffinose, and stachyose
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the enzyme is upregulated by several abiotic stresses
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ENGINEERING
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
additional information
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APPLICATION
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
agriculture
transgenic plants show constitutive resistance against fungal and bacterial pathogens and an increased tolerance to drought and high salinity stresses
additional information
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the enzyme an important target to reduce raffinose family oligosaccharides concentration in chickpea seeds
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LINKS TO OTHER DATABASES (specific for EC-Number 2.4.1.123)
ExplorEnz
ExPASy
KEGG
MetaCyc
SABIO-RK
NCBI: PubMed, Protein, Nucleotide, Structure, Genome, OMIM
IUBMB Enzyme Nomenclature
PROSITE Database of protein families and domains
InterPro (database of protein families, domains and functional sites)