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Information on EC 2.4.1.18 - 1,4-alpha-glucan branching enzyme and Organism(s) Oryza sativa and UniProt Accession Q01401
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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: Oryza sativa
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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amylose isomerase
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-
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BE
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-
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BEIIa
BEIIb
branching factor, enzymatic
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-
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branching glycosyltransferase
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-
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enzyme Q
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GBE
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glucosan transglycosylase
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glycogen branching enzyme
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glycosyltransferase, alpha-glucan-branching
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Q-enzyme
QE
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SBE
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starch branching enzyme
Q-enzyme
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starch branching enzyme
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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
?
assay at 30°C, reaction terminated by heating at 95°C for 5 min
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-
?
amylose
?
assay at 30°C, reaction terminated by heating at 95°C for 5 min
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-
?
additional information
?
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interactions between rice starch synthase isozymes and branching enzyme isozymes in the synthesis of unprimed glucan, overview
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?
additional information
?
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interactions between rice starch synthase isozymes and branching enzyme isozymes in the synthesis of unprimed glucan, overview
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-
?
additional information
?
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The activities of the isozymes BEi, BEIIa and BEIIb with a linear glucan amylose decrease with a decrease in the molar size of amylose, and no activities of BEIIa and BEIIb are found when the degree of polymerization of amylose is lower than at least 80, whereas BEI had an activity with amylose of a degree of polymerization higher than approximately 50. Isoform BEIIb almost exclusively transfers chains with degree of polymerization of 7 and 6 while isoform BEIIa forms a wide range of short chains with degree of polymerization of 6 to around 15 from outer chains of amylopectin and amylose. Isoform BEI forms a variety of short chains and intermediate chains of a degree of polymerization below 40 by attacking not only outer chains but also inner chains of branched glucan. Isoforms BEIIa or BEIIb can only scarcely or can not attack inner chains, respectively
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-
?
additional information
?
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-
interactions between rice SS isozymes and BE isozymes in the synthesis of unprimed glucan, overview
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-
?
additional information
?
-
interactions between rice SS isozymes and BE isozymes in the synthesis of unprimed glucan, overview
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-
?
METALS and IONS
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
ACTIVATING COMPOUND
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
starch synthase I
interaction between starch synthase I (SSI) and branching enzyme (BE) is established by stimulation of SSI activity with BE and by activation of the BE activity by SSI
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starch synthase I
interaction between starch synthase I (SSI) and branching enzyme (BE) is established by stimulation of SSI activity with BE and by activation of the BE activity by SSI
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KM VALUE [mM]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
0.00018
amylose
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amylose AS-1160, degree of polymerization of approximately 6,510, isoform BEI, pH 7.5, 30°C
0.0009
amylose
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amylose AS-1160, degree of polymerization of approximately 6,510, isoform BEI, pH 7.5, 30°C
0.0012
amylose
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amylose AS-1160, degree of polymerization of approximately 6,510, isoform BEI, pH 7.5, 30°C
additional information
additional information
-
Km-value for amylopectin is 3.0 mg/ml for isoform BEI, 2.7 mg/ml for isoform BEIIa, and 0.9 mg/ml for isoform BEIIb, 30°C, pH 7.0
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SPECIFIC ACTIVITY [µmol/min/mg]
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
additional information
additional information
2.5 U/mg for amylopectin, 1 U = decrease of one absorbance unit at 660 nm at 30°C
additional information
-
2.5 U/mg for amylopectin, 1 U = decrease of one absorbance unit at 660 nm at 30°C
additional information
20.8 U/mg for amylose, 1 U = decrease of one absorbance unit at 660 nm at 30°C
additional information
-
20.8 U/mg for amylose, 1 U = decrease of one absorbance unit at 660 nm at 30°C
additional information
-
1.229 U/mg for amylopectin, 1 U = 1% decrease of the absorbance/min
additional information
-
12.258 U/mg for amylose, 1 U = 1% decrease of the absorbance/min
pH OPTIMUM
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
7.5
TEMPERATURE OPTIMUM
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
30
ORGANISM
COMMENTARY
LITERATURE
UNIPROT
SEQUENCE DB
SOURCE
SOURCE TISSUE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
SOURCE
-
activity and expression level of branching enzyme 1 and branching enzyme 3 are lower at 29°C/35°C than those at 22°C/28°C. The decreased activity of starch branching enzyme reduces the branching frequency of the branches of amylopectin, which results in the increased amount of long chains of amylopectin of endosperm in rice grain at high temperature
GENERAL INFORMATION
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
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
physiological function
rice branching enzyme isozymes BEI, BEIIa, or BEIIb accelerate the reaction velocity of starch synthase SSI, but not of SSIIa or SSIIIa, in rice. The interaction between starch synthase I (SSI) and branching enzyme (BE) is established by stimulation of SSI activity with BE and by activation of the BE activity by SSI
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
physiological function
physiological function
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the synthesis of maltodextrins by alpha-glucan phosphorylase Pho1 is markedly accelerated by branching enzyme isozymes, with the greatest effect being exhibited by the presence of branching isozyme BEI rather than by isozyme BEIIa or isozyme BEIIb. The enhancement of the activity of Pho1 by branching enzymes is not merely due to the supply of a non-reducing ends. At the same time, Pho1 greatly enhances the branching enzyme activity, possibly by generating a branched carbohydrate substrate which is used by branching enzyme with a higher affinity. The interaction between Pho1 and branching enzyme is not merely due to chain-elongating and chain-branching reactions, but occurs in a physically and catalytically synergistic manner by each activating the mutual capacity of the other, presumably forming a physical association of Pho1, isoform BEI and branched maltodextrins
physiological function
rice branching enzyme isozymes BEI, BEIIa, or BEIIb accelerate the reaction velocity of starch synthase SSI, but not of SSIIa or SSIIIa, in rice. The interaction between starch synthase I (SSI) and branching enzyme (BE) is established by stimulation of SSI activity with BE and by activation of the BE activity by SSI
MOLECULAR WEIGHT
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
POSTTRANSLATIONAL MODIFICATION
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
proteolytic modification
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RBE4 is initially produced as a precursor protein of 841 amino acids, including a 53 residue transit peptide at the N-terminus
CRYSTALLIZATION (Commentary)
ORGANISM
UNIPROT
LITERATURE
determination of the crystal structure of branching enzyme I at a resolution of 1.9 A by molecular replacement using the Escherichia coli glycogen branching enzyme as a search model. Branching enzyme I is roughly ellipsoidal in shape with two globular domains that form a prominent groove proposed to serve as the alphha-polyglucan-binding site. Amino acid residues Asp344 and Glu399, postulated to play an essential role in catalysis, are located at a central cleft in the groove
mutant E399Q in complex with maltopentaose at a resolution of 2.2 A. Maltopentaose binds to a hydrophobic pocket formed by the N-terminal helix, carbohydrate-binding module 48, and alpha-amylase domain. In addition, glucose moieties can be observed at molecular surfaces on the N-terminal helix alpha2 and carbohydrate-binding module 48
PROTEIN VARIANTS
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
D270A
mutant with about 10% relative enzyme activity compared to wild-type enzyme
E399A
mutant with about 5% relative enzyme activity compared to wild-type enzyme
G468D
mutant with about 95% relative enzyme activity compared to wild-type enzyme
R342A
mutant with about 15% relative enzyme activity compared to wild-type enzyme
Y235A
mutant with about 15% relative enzyme activity compared to wild-type enzyme
PURIFICATION (Commentary)
ORGANISM
UNIPROT
LITERATURE
CLONED (Commentary)
ORGANISM
UNIPROT
LITERATURE
EXPRESSION
ORGANISM
UNIPROT
LITERATURE
REF.
AUTHORS
TITLE
JOURNAL
VOL.
PAGES
YEAR
ORGANISM (UNIPROT)
PUBMED ID
SOURCE
Nakamura, Y.; Takeichi, T.; Kawaguchi, K.; Yamanouchi, H.
Purification of two forms of starch branching enzyme (Q-enzyme) from developing rice endosperm
Physiol. Plant.
84
329-335
1992
Oryza sativa
-
Smyth, D.A.
Some properties of starch branching enzyme from indica rice endosperm (Oryzae sativa L.)
Plant Sci.
57
1-8
1988
Oryza sativa
-
Mizuno, K.; Kobayashi, E.; Tachibana, M.; Kawasaki, T.; Fujimura, T.; Funane, K.; Kobayashi, M.; Baba, T.
Characterization of an isoform of rice starch branching enzyme, RBE4, in developing seeds
Plant Cell Physiol.
42
349-357
2001
Oryza sativa
Mizuno, K.; Kamura, K.; Arai, Y.; Kawasaki, T.; Shimada, H.; Baba, T.
Starch branching enzymes from immature rice seeds
J. Biochem.
112
643-651
1992
Oryza sativa
Jiang, H.; Dian, W.; Wu, P.
Effect of high temperature on fine structure of amylopectin in rice endosperm by reducing the activity of the starch branching enzyme
Phytochemistry
63
53-59
2003
Oryza sativa
Yamanouchi, H.; Nakamura, Y.
Organ specificity of isoforms of starch branching enzyme (Q-enzyme) in rice
Plant Cell Physiol.
33
985 -991
1992
Oryza sativa
-
Vu, N.T.; Shimada, H.; Kakuta, Y.; Nakashima, T.; Ida, H.; Omori, T.; Nishi, A.; Satoh, H.; Kimura, M.
Biochemical and crystallographic characterization of the starch branching enzyme I (BEI) from Oryza sativa L
Biosci. Biotechnol. Biochem.
72
2858-2866
2008
Oryza sativa (Q01401), Oryza sativa
Akasaka, T.; Vu, N.T.; Chaen, K.; Nishi, A.; Satoh, H.; Ida, H.; Omori, T.; Kimura, M.
The action of rice branching enzyme I (BEI) on starches
Biosci. Biotechnol. Biochem.
73
2516-2518
2009
Oryza sativa
Sawada, T.; Francisco, P.B.; Aihara, S.; Utsumi, Y.; Yoshida, M.; Oyama, Y.; Tsuzuki, M.; Satoh, H.; Nakamura, Y.
Chlorella starch branching enzyme II (BEII) can complement the function of BEIIb in rice endosperm
Plant Cell Physiol.
50
1062-1074
2009
Oryza sativa, Parachlorella kessleri (A9ZPD1)
Chaen, K.; Noguchi, J.; Omori, T.; Kakuta, Y.; Kimura, M.
Crystal structure of the rice branching enzyme I (BEI) in complex with maltopentaose
Biochem. Biophys. Res. Commun.
424
508-511
2012
Oryza sativa (Q01401), Oryza sativa
Noguchi, J.; Chaen, K.; Vu, N.T.; Akasaka, T.; Shimada, H.; Nakashima, T.; Nishi, A.; Satoh, H.; Omori, T.; Kakuta, Y.; Kimura, M.
Crystal structure of the branching enzyme I (BEI) from Oryza sativa L with implications for catalysis and substrate binding
Glycobiology
21
1108-1116
2011
Oryza sativa (Q01401), Oryza sativa
Nakamura, Y.; Utsumi, Y.; Sawada, T.; Aihara, S.; Utsumi, C.; Yoshida, M.; Kitamura, S.
Characterization of the reactions of starch branching enzymes from rice endosperm
Plant Cell Physiol.
51
776-794
2010
Oryza sativa
Nakamura, Y.; Ono, M.; Utsumi, C.; Steup, M.
Functional interaction between plastidial starch phosphorylase and starch branching enzymes from rice during the synthesis of branched maltodextrins
Plant Cell Physiol.
53
869-878
2012
Oryza sativa
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)
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