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Information on EC 2.4.1.25 - 4-alpha-glucanotransferase and Organism(s) Thermus thermophilus and UniProt Accession O87172
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2.4.1.25 4-alpha-glucanotransferaseIUBMB Comments
This entry covers the former separate entry for EC 2.4.1.3 (amylomaltase). The plant enzyme has been termed D-enzyme. An enzymic activity of this nature forms part of the mammalian and yeast glycogen debranching system (see EC 3.2.1.33 amylo-alpha-1,6-glucosidase).
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Word Map
- 2.4.1.25
- starch
- maltose
- maltodextrins
- amylose
-
transglycosylation
- glucans
- amylopectin
- cycloamylose
-
disproportionation
- malto-oligosaccharides
- maltotetraose
- maltohexaose
- alpha-glucans
- maltopentaose
- synthesis
- alpha-amylases
- amylo-1,6-glucosidase
-
maltogenic
-
malpq
-
large-ring
- alpha-1,4-glucans
- biotechnology
- nutrition
- medicine
- analysis
- food industry
The taxonomic range for the selected organisms is: Thermus thermophilus
The expected taxonomic range for this enzyme is: Bacteria, Eukaryota, Archaea
The expected taxonomic range for this enzyme is: Bacteria, Eukaryota, Archaea
Synonyms
amylomaltase, d-enzyme, 4-alpha-glucanotransferase, disproportionating enzyme, amase, maltosyltransferase, alphagt, mq-01, alphagtase, pyamase, 
more
topSYNONYM 
ORGANISM
UNIPROT
COMMENTARY 
LITERATURE
amylomaltase
D-enzyme
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-
-
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debranching enzyme maltodextrin glycosyltransferase
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-
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dextrin glycosyltransferase
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-
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dextrin glycosyltransferase,
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-
-
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dextrin transglycosylase
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-
-
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disproportionating enzyme
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-
-
-
additional information
amylomaltase
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-
-
-
additional information
amylomaltases are glycosyl hydrolases belonging to glycoside hydrolase family 77
additional information
the enzyme belongs to the glycoside hydrolase family 77, GH77, which belongs to the alpha-amylase superfamily, Clan H, together with GH13 and GH70
REACTION
REACTION DIAGRAM
COMMENTARY
ORGANISM
UNIPROT
LITERATURE
Transfers a segment of a (1->4)-alpha-D-glucan to a new position in an acceptor, which may be glucose or a (1->4)-alpha-D-glucan
reaction mechanism and catalytic cycle, the catalytic nucleophile changes conformation dramatically during the reaction, Gln256 on the 250s loop is involved in orienting the substrate in the +1 site. The absence of a suitable base in the covalent intermediate structure explains the low hydrolysis activity, overview
REACTION TYPE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
hexosyl group transfer
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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 4-alpha-D-glycosyltransferase
This entry covers the former separate entry for EC 2.4.1.3 (amylomaltase). The plant enzyme has been termed D-enzyme. An enzymic activity of this nature forms part of the mammalian and yeast glycogen debranching system (see EC 3.2.1.33 amylo-alpha-1,6-glucosidase).
CAS REGISTRY NUMBER
COMMENTARY
9032-09-1
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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
maltotriose + maltotriose
glucose + maltooligosaccharides
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-
-
?
1,4-alpha-D-glucan + 1,4-alpha-D-glucan
maltooligosaccharides
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-
-
?
barley starch + glycosyl acceptor
?
-
transgenic barley amylose-only starch which consists of more than 99% amylose
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-
?
cassava starch + glycosyl acceptor
large ring-cyclodextrins 25-80
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-
-
-
?
maize starch + glycosyl acceptor
?
-
100% amylopectin waxy maize starch
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-
?
maltotriose + glycosyl acceptor
D-glucose + maltooligosaccharides
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-
-
-
?
additional information
?
-
amylomaltases are capable of the synthesis of large cyclic glucans and the disproportionation of oligosaccharides
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-
?
additional information
?
-
Thermus thermophilus AMase is among the most efficient 4-alpha-glucanotransferases in the alpha-amylase superfamily
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-
?
additional information
?
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glucose transfer/production using maltose and glycogen. Wild-type DPE2 can bind to starch and glycogen has very little, if any, ability to dissociate DPE2 from the starch pellet
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?
additional information
?
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substrates are maltooligomers, trimer to heptamer, substrate binding mechanism and structure, modeling. The active site contains at least seven substrate binding sites, subsites -2 and +3 favoring substrate binding and subsites -3 and +2 do not, substrate specificity, overview
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-
?
additional information
?
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glucose can only be used as acceptor of maltosyl units
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-
?
additional information
?
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preparation of gels from starches of various botanical origin, e.g. potato, high amylose potato, maize, waxy maize, wheat and pea starches, by modification through the enzyme from Thermus thermophilus, thermodynamics and product properties, overview
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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
?
-
amylomaltases are capable of the synthesis of large cyclic glucans and the disproportionation of oligosaccharides
-
-
?
additional information
?
-
Thermus thermophilus AMase is among the most efficient 4-alpha-glucanotransferases in the alpha-amylase superfamily
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-
?
INHIBITOR
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
acarbose
a strong mixed inhibitor with almost equal competitive and uncompetitive binding constants, acarbose is both bound in the active site and at another site
KM VALUE [mM]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
additional information
additional information
initial rate kintics
-
additional information
additional information
kinetics of wild-type and mutant enzymes at pH 6.5 and 70°C, overview
-
TURNOVER NUMBER [1/s]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
Ki VALUE [mM]
INHIBITOR
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
SPECIFIC ACTIVITY [µmol/min/mg]
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
pH OPTIMUM
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
pH RANGE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
4 - 7.5
pH dependence of wild-type and mutant enzymes, D293N and E340Q are active below pH 6.5 and pH 5.5, respectively, but precipitate during the necessary prolonged incubation times, wild-type Tt AMase precipitates below pH 5.5 under similar extended incubation times as well, overview
TEMPERATURE OPTIMUM
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
TEMPERATURE RANGE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
ORGANISM
COMMENTARY
LITERATURE
UNIPROT
SEQUENCE DB
SOURCE
UNIPROT
ENTRY NAME
ORGANISM
NO. OF AA
NO. OF TRANSM. HELICES
MOLECULAR WEIGHT[Da]
SOURCE
SEQUENCE
LOCALIZATION PREDICTION
The reliability class of the localization prediction ranges from 1 (very reliable) to 5 (not reliable).
The reliability class of the localization prediction ranges from 1 (very reliable) to 5 (not reliable). PDB
SCOP
CATH
UNIPROT
ORGANISM
MOLECULAR WEIGHT
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
SUBUNIT
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
CRYSTALLIZATION (Commentary)
ORGANISM
UNIPROT
LITERATURE
purified recombinant enzyme, hanging drop vapour diffusion method, 0.003 ml of protein solution containing 10 mM MES-NaOH, pH 6.5, with 1 mM dithiothreitol is mixed with 0.001-0.003 ml of reservoir solution containing 0.4-0.8 M sodium malonate, pH 5.6, and 1 mM dithiothreitol, equilibration against reservoir solution at room temperature, 1 week, for enzyme-acarbose complexing the crystals are soaked in 0.5 ml of 0.8 M sodium malonate, pH 5.6, with 5 mg/ml acarbose and with or without and 4-deoxyglucose, for 30 min, X-ray diffraction structure determination and analysis at 1.9-2.5 A resolution
PROTEIN VARIANTS
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
D293A
site-directed mutagenesis of the active site nucleophile, the mutant shows reduced activity with malto-oligomers compared to the wild-type enzyme
D293N
site-directed mutagenesis of the active site nucleophile, the D293N mutation reduces the pH stability of the enzyme, the mutant shows reduced activity with malto-oligomers compared to the wild-type enzyme
D294S
site-directed mutagenesis, the mutant shows highly reduced kcat and reduced activity with malto-oligomers compared to the wild-type enzyme
D395A
site-directed mutagenesis of the active site transition stabilizer, the mutant shows reduced activity with malto-oligomers compared to the wild-type enzyme
D395N
site-directed mutagenesis of the active site transition stabilizer, the mutant shows reduced activity with malto-oligomers compared to the wild-type enzyme
E340A
site-directed mutagenesis of the active site general acid/base catalyst, the mutant shows reduced activity with malto-oligomers compared to the wild-type enzyme
E340Q
site-directed mutagenesis of the active site general acid/base catalyst, the mutant shows reduced activity with malto-oligomers compared to the wild-type enzyme
E758Q
the mutant shows highly reduced activity compared to the wild-type enzyme
F366L
site-directed mutagenesis, the mutant shows reduced kcat compared and reduced activity with malto-oligomers compared to the wild-type enzyme
additional information
the deletion mutant DELTAN130 is unable to use glycogen but has high disproportionating activity with maltodextrins
pH STABILITY
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
TEMPERATURE STABILITY
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
PURIFICATION (Commentary)
ORGANISM
UNIPROT
LITERATURE
recombinant His-tagged enzyme from Escherichia coli strain BL21(DE3) by heat treatment and nickel affinity chromatography, removal of the His-tag through cleavage with bovine thrombin
CLONED (Commentary)
ORGANISM
UNIPROT
LITERATURE
expression of the His-tagged enzyme in Escherichia coli strain BL21(DE3)
APPLICATION
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
REF.
AUTHORS
TITLE
JOURNAL
VOL.
PAGES
YEAR
ORGANISM (UNIPROT)
PUBMED ID
SOURCE
Van der Maarel, M.J.E.C.; Euverink, G.J.W.; Binnema, D.J.; Bos, H.T.P.; Bergsma, J.
Amylomaltase from the hyperthermophilic bacterium Thermus thermophilus: Enzyme characteristics and application in the starch industry
Meded. -Fac. Landbouwkd. Toegepaste Biol. Wet.
65
231-234
2000
Thermus thermophilus, Solanum tuberosum
-
Kaper, T.; Leemhuis, H.; Uitdehaag, J.C.; van der Veen, B.A.; Dijkstra, B.W.; van der Maarel, M.J.; Dijkhuizen, L.
Identification of acceptor substrate binding subsites +2 and +3 in the amylomaltase from Thermus thermophilus HB8
Biochemistry
46
5261-5269
2007
Thermus thermophilus (O87172), Thermus thermophilus HB8 / ATCC 27634 / DSM 579 (O87172)
Barends, T.R.; Bultema, J.B.; Kaper, T.; van der Maarel, M.J.; Dijkhuizen, L.; Dijkstra, B.W.
Three-way stabilization of the covalent intermediate in amylomaltase, an alpha-amylase-like transglycosylase
J. Biol. Chem.
282
17242-17249
2007
Thermus thermophilus (O87172)
Hansen, M.; Blennow, A.; Pedersen, S.; Engelsen, S.
Enzyme modification of starch with amylomaltase results in increasing gel melting point
Carbohydr. Polym.
78
72-79
2009
Thermus thermophilus
Sorndech, W.; Sagnelli, D.; Meier, S.; Jansson, A.M.; Lee, B.H.; Hamaker, B.R.; Rolland-Sabate, A.; Hebelstrup, K.H.; Tongta, S.; Blennow, A.
Structure of branching enzyme- and amylomaltase modified starch produced from well-defined amylose to amylopectin substrates
Carbohydr. Polym.
152
51-61
2016
Thermus thermophilus
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