Information on EC 2.4.1.184 - galactolipid galactosyltransferase

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

EC NUMBER
COMMENTARY hide
2.4.1.184
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RECOMMENDED NAME
GeneOntology No.
galactolipid galactosyltransferase
REACTION
REACTION DIAGRAM
COMMENTARY hide
ORGANISM
UNIPROT
LITERATURE
2 a 1,2-diacyl-3-O-(beta-D-galactosyl)-sn-glycerol = a 1,2-diacyl-3-O-[beta-D-galactosyl-(1->6)-beta-D-galactosyl]-sn-glycerol + a 1,2-diacyl-sn-glycerol
show the reaction diagram
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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
galactolipid biosynthesis I
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Glycerolipid metabolism
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SYSTEMATIC NAME
IUBMB Comments
1,2-diacyl-3-O-(beta-D-galactosyl)-sn-glycerol:1,2-diacyl-3-O-(beta-D-galactosyl)-sn-glycerol beta-D-galactosyltransferase
The enzyme converts monogalactosyldiacylglycerol to digalactosyldiacylglycerol, trigalactosyldiacylglycerol and tetragalactosyldiacylglycerol. All residues are connected by beta linkages. The activity is localized to chloroplast envelope membranes, but it does not contribute to net galactolipid synthesis in plants, which is performed by EC 2.4.1.46, monogalactosyldiacylglycerol synthase, and EC 2.4.1.241, digalactosyldiacylglycerol synthase. Note that the beta,beta-digalactosyldiacylglycerol formed by this enzyme is different from the more common alpha,beta-digalactosyldiacylglycerol formed by EC 2.4.1.241. The enzyme provides an important mechanism for the stabilization of the chloroplast membranes during freezing and drought stress.
CAS REGISTRY NUMBER
COMMENTARY hide
66676-74-2
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ORGANISM
COMMENTARY hide
LITERATURE
UNIPROT
SEQUENCE DB
SOURCE
in the lipid extract form cells expressing chlo02003782 monogalactosyldiacylglycerol is detected, therefor, this open reading frame is assigned as a beta-galactosyltransferase
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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
1,2-diacyl-3-O-(beta-D-galactosyl)-sn-glycerol + 1,2-diacyl-3-O-(beta-D-galactosyl)-sn-glycerol
1,2-diacyl-3-O-[alpha-D-galactosyl-(1->6)-beta-D-galactosyl]-sn-glycerol + 1,2-diacyl-sn-glycerol
show the reaction diagram
additional information
?
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enzyme isoform Dgd2 is crucial for synthesis of additional digalactosyldiacylglycerol during phosphate deprivation
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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
1,2-diacyl-3-O-(beta-D-galactosyl)-sn-glycerol + 1,2-diacyl-3-O-(beta-D-galactosyl)-sn-glycerol
1,2-diacyl-3-O-[alpha-D-galactosyl-(1->6)-beta-D-galactosyl]-sn-glycerol + 1,2-diacyl-sn-glycerol
show the reaction diagram
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?
additional information
?
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enzyme isoform Dgd2 is crucial for synthesis of additional digalactosyldiacylglycerol during phosphate deprivation
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METALS and IONS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
Ba2+
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10 mM, 23fold stimulation
Co2+
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10 mM, 3fold simulation
Fe2+
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10 mM, 6fold simulation
Li+
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50 mM, weak stimulation
Na+
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50 mM, weak stimulation
INHIBITORS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
CdCl2
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2 mM, 50% inhibition
N-ethylmaleimide
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p-hydroxymercuribenzoate
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Thermolysin
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UMP
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10 mM, 50% inhibition
ACTIVATING COMPOUND
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
alpha-linolenic acid
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0.3 mM, 28fold stimulation in the presence of 2 mM MgCl2, MgCl2 can be replaced by MnCl2, CaCl2 or high concetrations of KCl
hexadecatrienoic acid
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approx. 3fold activation
linoleic acid
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approx. 4fold activiation
NH4+
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50 mM, 5fold stimulation
oleic acid
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approx. 4fold activiation
palmitic acid
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approx. 2fold activiation
palmitoleic acid
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approx. 4fold activiation
stearic acid
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approx. 2fold activiation
additional information
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activated by free fatty acids in the presence of divalent cations such as Mg2+ following ozone fumigation
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pH OPTIMUM
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
6 - 7
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forward reaction
6.5
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reverse reaction
8
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assay at
pH RANGE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
4.7 - 8.9
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approx. 50% of maximal activity at pH 5.3 and pH 8.0
TEMPERATURE OPTIMUM
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
30
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assay at
TEMPERATURE RANGE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
4 - 30
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still active at 4°C
SOURCE TISSUE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
SOURCE
LOCALIZATION
ORGANISM
UNIPROT
COMMENTARY hide
GeneOntology No.
LITERATURE
SOURCE
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outer side of envolepe membrane, Dgd2, plus a third enzymic activity
Manually annotated by BRENDA team
additional information
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sensitivity to thermolysin suggests that the enzyme is located on the outside of the outer envelope of the chloroplast
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Manually annotated by BRENDA team
Cloned/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
expressed in Synechococcus cerevisiae
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ENGINEERING
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
additional information