EzCatDB: S00202

DB codeS00202
RLCP classification3.900.275800.990
CATH domainDomain 13.20.20.80Catalytic domain
E.C.2.4.1.25
CSA1cwy

CATH domainRelated DB codes (homologues)
3.20.20.80S00210,S00748,S00906,S00907,S00911,S00912,S00915,M00134,M00160,D00479,S00204,S00205,S00206,S00207,S00203,S00208,S00209,S00211,S00213,S00214,M00113,T00307,D00165,D00166,D00169,D00176,D00501,D00502,D00503,D00844,D00861,D00864,M00026,M00112,M00193,M00346,T00057,T00062,T00063,T00066,T00067

Enzyme Name
Swiss-protKEGG

O87172
Protein name4-alpha-glucanotransferase4-alpha-glucanotransferase
disproportionating enzyme
dextrin glycosyltransferase
D-enzyme
debranching enzyme maltodextrin glycosyltransferase
amylomaltase
dextrin transglycosylase
1,4-alpha-D-glucan:1,4-alpha-D-glucan 4-alpha-D-glycosyltransferase
SynonymsEC 2.4.1.25
Amylomaltase
Disproportionating enzyme
D-enzyme

KEGG pathways
MAP codePathways
MAP00500Starch and sucrose metabolism

Swiss-prot:Accession NumberO87172
Entry nameMALQ_THETH
ActivityTransfers 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.
Subunit
Subcellular locationCytoplasm (By similarity).
Cofactor


SubstratesProducts
KEGG-idC00718C00293C00208
CompoundAmyloseGlucoseMaltose
Typepolysaccharidecarbohydratepolysaccharide
1cwyAUnboundUnboundUnbound
1eswAAnalogue:ACR 651UnboundUnbound
1fp8AUnboundUnboundUnbound
1fp9AUnboundUnboundUnbound

Active-site residues
resource
literature [11]
pdbCatalytic residues
1cwyAASP 293;GLU 340;HIS 394;ASP 395
1eswAASP 293;GLU 340;HIS 394;ASP 395
1fp8AASP 293;GLU 340;HIS 394;ASP 395
1fp9AASP 293;GLU 340;HIS 394;ASP 395

References for Catalytic Mechanism
ReferencesSectionsNo. of steps in catalysis
[7]p.1057
[10]p.6910-6911
[11]Fig.1, p.879-882

references
[1]
PubMed ID2086786
JournalJ Protozool
Year1990
Volume37
Pages576-80
AuthorsWerries E, Franz A, Geisemeyer S
TitleDetection of glycogen-debranching system in trophozoites of Entamoeba histolytica
[2]
PubMed ID7678257
JournalJ Biol Chem
Year1993
Volume268
Pages1391-6
AuthorsTakaha T, Yanase M, Okada S, Smith SM
TitleDisproportionating enzyme (4-alpha-glucanotransferase; EC 2.4.1.25) of potato. Purification, molecular cloning, and potential role in starch metabolism
[3]
PubMed ID85430201
JournalFEBS Lett
Year1995
Volume377
Pages6-8
AuthorsJanecek S
TitleClose evolutionary relatedness among functionally distantly related members of the (alpha/beta)8-barrel glycosyl hydrolases suggested by the similarity of their fifth conserved sequence region
[4]
PubMed ID8621678
JournalJ Biol Chem
Year1996
Volume271
Pages2902-8
AuthorsTakaha T, Yanase M, Takata H, Okada S, Smith SM
TitlePotato D-enzyme catalyzes the cyclization of amylose to produce cycloamylose, a novel cyclic glucan
[5]
PubMed ID9353929
JournalMicrobiology
Year1997
Volume143
Pages3287-94
AuthorsGoda SK, Eissa O, Akhtar M, Minton NP
TitleMolecular analysis of a Clostridium butyricum NCIMB 7423 gene encoding 4-alpha-glucanotransferase and characterization of the recombinant enzyme produced in Escherichia coli
[6]
PubMed ID9642157
JournalBiochem Biophys Res Commun
Year1998
Volume247
Pages493-7
AuthorsTakaha T, Yanase M, Takata H, Okada S, Smith SM
TitleCyclic glucans produced by the intramolecular transglycosylation activity of potato D-enzyme on amylopectin
[7]
PubMed ID9990324
JournalEur J Biochem
Year1998
Volume258
Pages1050-8
AuthorsMeissner H, Liebl W
TitleThermotoga maritima maltosyltransferase, a novel type of maltodextrin glycosyltransferase acting on starch and malto-oligosaccharides
[8]
PubMed ID10049841
JournalAppl Environ Microbiol
Year1999
Volume65
Pages910-5
AuthorsTerada Y, Fujii K, Takaha T, Okada S
TitleThermus aquaticus ATCC 33923 amylomaltase gene cloning and expression and enzyme characterization
[9]
PubMed ID10380338
JournalBiopolymers
Year1999
Volume50
Pages145-51
AuthorsNakatani H
TitleMonte Carlo simulation of 4-alpha-glucanotransferase reaction
[10]
CommentsX-ray crystallography
PubMed ID11082203
JournalEur J Biochem
Year2000
Volume267
Pages6903-13
AuthorsPrzylas I, Terada Y, Fujii K, Takaha T, Saenger W, Strater N
TitleX-ray structure of acarbose bound to amylomaltase from Thermus aquaticus. Implications for the synthesis of large cyclic glucans
Related PDB1esw
[11]
CommentsX-RAY CRYSTALLOGRAPHY (2.0 ANGSTROMS).
Medline ID20143895
PubMed ID10677288
JournalJ Mol Biol
Year2000
Volume296
Pages873-86
AuthorsPrzylas I, Tomoo K, Terada Y, Takaha T, Fujii K, Saenger W, Strater N
TitleCrystal structure of amylomaltase from thermus aquaticus, a glycosyltransferase catalysing the production of large cyclic glucans
Related PDB1cwy
Related Swiss-protO87172

comments
This enzyme is homologous to glycosidase family-13, to which alpha-amylase belongs. This family has a retaining mechanism.
These structures would be a part of Glycogen Debranching Enzyme System that has both of 4-alpha-glucanotransferase (EC 2.4.1.25) and amylo-1,6-glucosidase (EC 3.2.1.33) activities.
This enzyme can catalyze the cyclization of amylose, with intramolecular transfer reaction. The reaction proceeds as follows (see [11]):
(1) Glu340 acts as a general acid to protonate the glycosidic oxygen atom of the scissile bond, forming a oxocarbenium-like transition state. Here, Asp395 and His394 probably stabilize the transition state. (SN1-like reaction)
(2) Asp293 acts as a nucleophile to make an attack on the C1 atom of the substrate, forming the covalent intermediate.
(3) Glu340 now acts as a general base, to deprotonate the acceptor group, hydroxyl group.
(4) The activated acceptor group makes another nucleophilic attack on the C1 atom, to form a new covalent bond.

createdupdated
2004-03-222011-11-30
Copyright: Nozomi Nagano, JST & CBRC-AIST
Funded by PRESTO/Japan Science and Technology Corporation (JST) (December 2001 - November 2004)
Funded by Grant-in-Aid for Publication of Scientific Research Results/Japan Society for the Promotion of Science (JSPS) (April 2005 - March 2006)
Funded by Grant-in-Aid for Scientific Research (B)/Japan Society for the Promotion of Science (JSPS) (April 2005 - March 2008)
Funded by BIRD/Japan Science and Technology Corporation (JST) (September 2005 - September 2010)
Funded by BIRD/Japan Science and Technology Corporation (JST) (October 2007 - September 2010)
Funded by Grant-in-Aid for Publication of Scientific Research Results/Japan Society for the Promotion of Science (JSPS) (April 2011 - March 2012)

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