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Information on EC 2.4.1.18 - 1,4-alpha-glucan branching enzyme and Organism(s) Escherichia coli and UniProt Accession P07762
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2.4.1.18 1,4-alpha-glucan branching enzymeIUBMB Comments
Converts amylose into amylopectin. The accepted name requires a qualification depending on the product, glycogen or amylopectin, e.g. glycogen branching enzyme, amylopectin branching enzyme. The latter has frequently been termed Q-enzyme.
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Word Map
- 2.4.1.18
- biloba
- ginkgo
- amylopectin
- endosperm
- maize
- grain
-
pyrophosphorylase
- phosphorylase
-
granule-bound
- glucans
- potato
-
debranching
- polysaccharide
-
polyglucosan
-
herbal
- ssiia
-
ginkgolide
- kernel
- gelatin
-
waxy
- glycogenosis
- amyloplasts
- pullulanase
- andersen
- dextrin
- isoamylase
- bilobalide
- agpase
-
high-amylose
-
amylolytic
-
chain-length
-
lafora
-
rhodothermus
- biotechnology
- medicine
- adpglucose
- glycogenin
- food industry
- nutrition
-
diastase-resistant
- alpha-glucans
- drug development
-
pas-positive
- isorhamnetin
The taxonomic range for the selected organisms is: Escherichia coli
The enzyme appears in selected viruses and cellular organisms
The enzyme appears in selected viruses and cellular organisms
Synonyms
gbe, branching enzyme, sbeiib, glycogen branching enzyme, starch branching enzyme, sbeiia, beiib, sbeii, starch-branching enzyme, beiia, 
more
topSYNONYM 
ORGANISM
UNIPROT
COMMENTARY 
LITERATURE
alpha-1,4-glucan:alpha-1,4-glucan 6-glycosyltransferase
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alpha-1,4-glucan:alpha-1,4-glucan-6-glycosyltransferase
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alpha-glucan-branching glycosyltransferase
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amylo-(1,4-1,6)-transglycosylase
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-
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amylose isomerase
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-
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BE
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-
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branching factor, enzymatic
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branching glycosyltransferase
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enzyme Q
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GBE
glucosan transglycosylase
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glycogen branching enzyme
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-
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glycosyltransferase, alpha-glucan-branching
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Q-enzyme
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QE
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SBE
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starch branching enzyme
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GBE
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REACTION TYPE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
glycosyl group transfer
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-
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PATHWAY SOURCE
PATHWAYS
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-, -, -, -
SYSTEMATIC NAME
IUBMB Comments
(1->4)-alpha-D-glucan:(1->4)-alpha-D-glucan 6-alpha-D-[(1->4)-alpha-D-glucano]-transferase
Converts amylose into amylopectin. The accepted name requires a qualification depending on the product, glycogen or amylopectin, e.g. glycogen branching enzyme, amylopectin branching enzyme. The latter has frequently been termed Q-enzyme.
CAS REGISTRY NUMBER
COMMENTARY
9001-97-2
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SUBSTRATE
PRODUCT
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate)
(Substrate)
LITERATURE
(Substrate)
(Substrate)
COMMENTARY
(Product)
(Product)
LITERATURE
(Product)
(Product)
Reversibility
r=reversible
ir=irreversible
?=not specified
r=reversible
ir=irreversible
?=not specified
amylopectin
amylopectin with additional alpha-1,6-glucosidic linkages
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-
-
-
?
amylopectin
amylopectin with additional alpha-1,6-glucosidic linkages
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the wild-type enzyme transfers mainly chains with a degree of polymerization of 8-14, the mutant enzyme DELTA1-112 transfers a greater propertion of chains with higher degree of polymerization, 15-20. Mutant DELTA1-63 and mutant DELTA1-83 have an intermediate pattern of transferred chains, 10-20. A progressive shortening of the N-terminus leads to a gradual increase in the length of the transferred chains
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-
?
amylose
amylose containing alpha-1,6-glucosidic linkages
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-
characterization of products, smallest chains transferred contain 5-7 glucose units
?
amylose
amylose containing alpha-1,6-glucosidic linkages
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wild-type enzyme and mutant enzyme Y300F both preferentially transfer chains between DP5 and DP16, with a chain of DP11 being transferred at the highest frequency
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-
?
amylose
amylose containing alpha-1,6-glucosidic linkages
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the wild-type enzyme transfers mainly chains with a degree of polymerization of 8-14, the mutant enzyme DELTA1-112 transfers a greater proportion of chains with higher degree of polymerization, 15-20. Mutant DELTA1-63 and mutant DELTA1-83 have an intermediate pattern of transferred chains, 10-20. A progressive shortening of the N-terminus leads to a gradual increase in the length of the transferred chains
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-
?
additional information
?
-
the Escherichia coli enzyme specifically forms the branch linkages at the third glucose residue from the reducing end of the acceptor chain. The enzyme recognizes the location of branching points in its acceptor chain during their branching reaction
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-
?
additional information
?
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-
the enzyme is responsible for the formation of the alpha-1,6 linkages in the glycogen molecule
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-
?
NATURAL SUBSTRATE
NATURAL PRODUCT
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate)
(Substrate)
LITERATURE
(Substrate)
(Substrate)
COMMENTARY
(Product)
(Product)
LITERATURE
(Product)
(Product)
REVERSIBILITY
r=reversible
ir=irreversible
?=not specified
r=reversible
ir=irreversible
?=not specified
additional information
?
-
-
the enzyme is responsible for the formation of the alpha-1,6 linkages in the glycogen molecule
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-
?
KM VALUE [mM]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
SPECIFIC ACTIVITY [µmol/min/mg]
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
28.5
-
mutant enzyme DELTA1-63, micromol Glc incorporated into alpha-D-glucan per min at 30°C
535.4
-
mutant enzyme DELTA1-83, micromol Glc incorporated into alpha-D-glucan per min at 30°C
pH OPTIMUM
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
TEMPERATURE OPTIMUM
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
ORGANISM
COMMENTARY
LITERATURE
UNIPROT
SEQUENCE DB
SOURCE
SOURCE TISSUE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
SOURCE
-
of transgenic rice, expression of Escherichia coli branching enzyme in caryopses of transgenic Oryza sativa
LOCALIZATION
ORGANISM
UNIPROT
COMMENTARY
GeneOntology No.
LITERATURE
SOURCE
-
the purified full-length enzyme is poorly soluble and forms aggregates, which are inactive, at concentrations above 1 mg/ml. In contrast, the truncated form can be concentrated to 6 mg/ml without a visible sign of aggregation or loss of activity on concentration
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GENERAL INFORMATION
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
evolution
malfunction
mutations of conserved residues in binding sites I and VI have a debilitating effect on the activity of the enzyme
metabolism
the balance between branching and debranching is crucial for the synthesis of starch, as an excess of branching activity results in the formation of highly branched, water-soluble, poorly crystalline polyglucan
physiological function
additional information
evolution
great variation exists as to the preference of branching enzymes of diffeent species for their acceptor chain, either A-chain or B-chain. Phylogenetic tree of alpha-glucan branching enzymes
evolution
the branching enzyme is an unusual member of the alpha-amylase family because it has both alpha-1,4-amylase activity and alpha-1,6-transferase activity
physiological function
starch synthesis requires several enzymatic activities including branching enzymes (BEs) responsible for the formation of alpha(1->6) linkages. Distribution and number of these linkages are further controlled by debranching enzymes that cleave some of them, rendering the polyglucan water-insoluble and semi-crystalline. The activity of BEs and debranching enzymes is mandatory to sustain normal starch synthesis
physiological function
the branching enzyme is responsible for all branching of glycogen and starch. It has both alpha-1,4-amylase activity and alpha-1,6-transferase activity
additional information
six distinct oligosaccharide binding sites on the surface of the branching enzyme, most of which surround the edge of the beta-barrel domain and are quite far from the active site. No evidence of oligosaccharide binding in the active site of the enzyme, the closest bound oligosaccharide resides almost 18 A from the active site
additional information
-
six distinct oligosaccharide binding sites on the surface of the branching enzyme, most of which surround the edge of the beta-barrel domain and are quite far from the active site. No evidence of oligosaccharide binding in the active site of the enzyme, the closest bound oligosaccharide resides almost 18 A from the active site
additional information
the branching enzyme's origin has only a limited impact on establishing essential characteristics of starch
additional information
-
the branching enzyme's origin has only a limited impact on establishing essential characteristics of starch
PDB
SCOP
CATH
UNIPROT
ORGANISM
MOLECULAR WEIGHT
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
SUBUNIT
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
additional information
additional information
six distinct oligosaccharide binding sites on the surface of the branching enzyme, most of which surround the edge of the beta-barrel domain and are quite far from the active site
additional information
-
six distinct oligosaccharide binding sites on the surface of the branching enzyme, most of which surround the edge of the beta-barrel domain and are quite far from the active site
CRYSTALLIZATION (Commentary)
ORGANISM
UNIPROT
LITERATURE
crystal structures of truncated branching enzyme mutant DELTA112 in complex with linear oligosaccharides maltoheptaose and maltohexaose, X-ray diffraction structure determination and analysis
hanging drop method, active N-terminally truncated form missing the first 107 amino acids
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PROTEIN VARIANTS
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
DELTA1-112
DELTA1-63
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the wild-type enzyme transfers mainly chains with a degree of polymerization of 8-14, mutant enzyme has a pattern of transferred chains, 10-20
DELTA1-83
-
the wild-type enzyme transfers mainly chains with a degree of polymerization of 8-14, mutant enzyme has a pattern of transferred chains, 10-20
truncated enzyme form missing the first 107 amino-
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the purified full-length enzyme is poorly soluble and forms aggregates, which are inactive, at concentrations above 1 mg/ml. In contrast, the truncated form can be concentrated to 6 mg/ml without a visible signs of aggregation or loss of activity on concentration
Y300F
-
mutant enzyme shows 25% of the wild-type activity, no effect on Km-value, heat stability is lowered significantly compared to that of the wild-type enzyme, lower relative activity at elevated temperatures compared to wild-type enzyme
DELTA1-112
-
the wild-type enzyme transfers mainly chains with a degree of polymerization of 8-14, the mutant enzyme DELTA1-112 transfers a greater propertion of chains with higher degree of polymerization, 15-20
DELTA1-112
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truncated enzyme transferrs a greater amount of longer chains than the wild-type enzyme
STORAGE STABILITY
ORGANISM
UNIPROT
LITERATURE
PURIFICATION (Commentary)
ORGANISM
UNIPROT
LITERATURE
CLONED (Commentary)
ORGANISM
UNIPROT
LITERATURE
gene glgB, functional recombinant expression of the bacterial enzyme in Arabidopsis thaliana be2 be3 double mutant leaves, ecotype WS, which is devoid of BE activity and consequently free of starch. The synthesis of a water-insoluble, partly crystalline, amylose-containing starch-like polyglucan is restored in GlgB-expressing transgenic plants, morphology of purified insoluble and soluble polyglucans, phenotype, overview
expression in Escherichia coli, full-length enzyme and a truncated enzyme form missing the first 107 amino acids
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expression of Escherichia coli branching enzyme in caryopses of transgenic Oryza satica results in amylopectin with an increased degree of branching. Expression of Escgerichia coli glgB in rice results in an increase in the short-chain fractions with DP between 6 and 10, which should have a significant effect on retrogradation
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APPLICATION
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
nutrition
-
cooking and textural characteristics of rice depend not only on the ratio of amylose, but also on the degree of amylopectin branching. Short chains of glucose with a degree of polymerization (DP)of 69 inhibit retrogradation. In vivo modification of starches using genetic engineering holds potential for both enhancing nutritional qualities and for obviating post-harvest modifications often necessary for utilization of this complex carbohydrate
REF.
AUTHORS
TITLE
JOURNAL
VOL.
PAGES
YEAR
ORGANISM (UNIPROT)
PUBMED ID
SOURCE
Holmes, E.; Boyer, C.; Preiss, J.
Immunological characterization of Escherichia coli B glycogen synthase and branching enzyme and comparison with enzymes from other bacteria
J. Bacteriol.
151
1444-1453
1982
Escherichia coli, Escherichia coli B / ATCC 11303
Boyer, C.; Preiss, J.
Biosynthesis of bacterial glycogen. Purification and properties of the Escherichia coli b alpha-1,4-glucan: alpha-1,4-glucan 6-glycosyltansferase
Biochemistry
16
3693-3699
1977
Escherichia coli
Abad, M.C.; Binderup, K.; Rios-Steiner, J.; Arni, R.K.; Preiss, J.; Geiger, J.H.
The X-ray crystallographic structure of Escherichia coli branching enzyme
J. Biol. Chem.
277
42164-42170
2002
Escherichia coli
Hilden, I.; Leggio, L.L.; Larsen, S.; Poulsen, P.
Characterization and crystallization of an active N-terminally truncated form of the Escherichia coli glycogen branching enzyme
Eur. J. Biochem.
267
2150-2155
2000
Escherichia coli
Mikkelsen, R.; Binderup, K.; Preiss, J.
Tyrosine residue 300 is important for activity and stability of branching enzyme from Escherichia coli
Arch. Biochem. Biophys.
385
372-377
2001
Escherichia coli
Binderup, K.; Mikkelsen, J.; Preiss, J.
Truncation of the amino terminus of branching enzyme changes its transfer pattern
Arch. Biochem. Biophys.
397
279-285
2002
Escherichia coli
Devillers, C.H.; Piper, M.E.; Ballicora, M.A.; Preiss, J.
Characterization of the branching patterns of glycogen branching enzyme truncated on the N-terminus
Arch. Biochem. Biophys.
418
34-38
2003
Escherichia coli
Kim, W.S.; Kim, J.; Krishnan, H.B.; Nahm, B.H.
Expression of Escherichia coli branching enzyme in caryopses of transgenic rice results in amylopectin with an increased degree of branching
Planta
220
689-695
2005
Escherichia coli
Sawada, T.; Nakamura, Y.; Ohdan, T.; Saitoh, A.; Francisco, P.B.; Suzuki, E.; Fujita, N.; Shimonaga, T.; Fujiwara, S.; Tsuzuki, M.; Colleoni, C.; Ball, S.
Diversity of reaction characteristics of glucan branching enzymes and the fine structure of alpha-glucan from various sources
Arch. Biochem. Biophys.
562
9-21
2014
Homo sapiens, Porphyridium purpureum, Parachlorella kessleri (A9ZPD1), Parachlorella kessleri, Escherichia coli (P07762), Synechococcus elongatus (P16954), Synechococcus elongatus, Oryza sativa (Q01401), Oryza sativa (Q40733), Oryza sativa (Q6H6P8), Oryza sativa, Synechococcus elongatus PCC 7942 (P16954)
Feng, L.; Fawaz, R.; Hovde, S.; Gilbert, L.; Chiou, J.; Geiger, J.H.
Crystal structures of Escherichia coli branching enzyme in complex with linear oligosaccharides
Biochemistry
54
6207-6218
2015
Escherichia coli (P07762), Escherichia coli
Boyer, L.; Roussel, X.; Courseaux, A.; Ndjindji, O.; Lancelon-Pin, C.; Putaux, J.; Tetlow, I.; Emes, M.; Pontoire, B.; D Hulst, C.; Wattebled, F.
Expression of Escherichia coli glycogen branching enzyme in an Arabidopsis mutant devoid of endogenous starch branching enzymes induces the synthesis of starch-like polyglucans
Plant Cell Environ.
39
1432-1447
2016
Escherichia coli (P07762), Escherichia coli
Wang, L.; Liu, Q.; Hu, J.; Asenso, J.; Wise, M.J.; Wu, X.; Ma, C.; Chen, X.; Yang, J.; Tang, D.
Structure and evolution of glycogen branching enzyme N-termini from bacteria
Front. Microbiol.
9
3354
2018
Escherichia coli (P07762), Bacillus subtilis (P39118), Frankia casuarinae (Q2J6Q9), Burkholderia thailandensis (Q2T6R3), Streptomyces avermitilis (Q82JF0), Bacillus subtilis 168 (P39118), Burkholderia thailandensis ATCC 700388 (Q2T6R3), Frankia casuarinae DSM 45818 (Q2J6Q9), Streptomyces avermitilis ATCC 31267 (Q82JF0)
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