EzCatDB: T00067

DB codeT00067
RLCP classification1.30.36000.3
CATH domainDomain 12.60.40.10
Domain 23.20.20.80Catalytic domain
Domain 32.60.40.1180
E.C.3.2.1.68
CSA1bf2

CATH domainRelated DB codes (homologues)
2.60.40.10M00131,T00257,T00005,M00113,M00127,M00132,M00323,M00325,M00327,M00329,M00330,M00331,M00332,T00307,D00166,D00500,M00112,M00193,T00063,T00065,T00245
2.60.40.1180M00113,T00307,D00165,D00176,D00664,D00665,D00863,D00864,M00112,M00193,M00314,T00057,T00062
3.20.20.80S00202,S00210,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

Enzyme Name
Swiss-protKEGG

P10342
Protein nameIsoamylaseisoamylase
debranching enzyme
glycogen alpha-1,6-glucanohydrolase
SynonymsEC 3.2.1.68


Swiss-prot:Accession NumberP10342
Entry nameISOA_PSEAY
ActivityHydrolysis of (1->6)-alpha-D-glucosidic branch linkages in glycogen, amylopectin and their beta-limit dextrins.
SubunitMonomer.
Subcellular location
CofactorBinds 1 calcium ion per subunit.


SubstratesProducts
KEGG-idC00182C00317C00001C00718C00721
CompoundGlycogenAmylopectinH2OAmyloseDextrin
TypepolysaccharidepolysaccharideH2Opolysaccharidepolysaccharide
1bf2A01UnboundUnbound
UnboundUnbound
1bf2A02UnboundUnbound
UnboundUnbound
1bf2A03UnboundUnbound
UnboundUnbound

Active-site residues
resource
Swiss-prot;P10342 & literature [3]
pdbCatalytic residues
1bf2A01
1bf2A02ASP 375;GLU 435;ASP 510
1bf2A03

References for Catalytic Mechanism
ReferencesSectionsNo. of steps in catalysis
[3]p.890-892
[4]Fig.2, p.4-5, p.11

references
[1]
PubMed ID7175943
JournalJ Mol Biol
Year1982
Volume160
Pages669-71
AuthorsSato M, Hato Y, Ii Y, Miki K, Kasai N, Tanaka N, Harada T
TitlePreliminary x-ray studies on Pseudomonas isoamylase.
[2]
PubMed ID1388153
JournalJ Biol Chem
Year1992
Volume267
Pages18447-52
AuthorsTakata H, Kuriki T, Okada S, Takesada Y, Iizuka M, Minamiura N, Imanaka T
TitleAction of neopullulanase. Neopullulanase catalyzes both hydrolysis and transglycosylation at alpha-(1----4)- and alpha-(1----6)-glucosidic linkages.
[3]
CommentsX-RAY CRYSTALLOGRAPHY (2.0 ANGSTROMS).
Medline ID98387895
PubMed ID9719642
JournalJ Mol Biol
Year1998
Volume281
Pages885-97
AuthorsKatsuya Y, Mezaki Y, Kubota M, Matsuura Y
TitleThree-dimensional structure of Pseudomonas isoamylase at 2.2 A resolution.
Related PDB1bf2
Related Swiss-protP10342
[4]
PubMed ID11257505
JournalBiochim Biophys Acta
Year2001
Volume1546
Pages1-20
AuthorsMacGregor EA, Janecek S, Svensson B
TitleRelationship of sequence and structure to specificity in the alpha-amylase family of enzymes.
[5]
PubMed ID12509527
JournalPlant Cell
Year2003
Volume15
Pages133-49
AuthorsHussain H, Mant A, Seale R, Zeeman S, Hinchliffe E, Edwards A, Hylton C, Bornemann S, Smith AM, Martin C, Bustos R
TitleThree isoforms of isoamylase contribute different catalytic properties for the debranching of potato glucans.

comments
This enzyme belongs to the glycosyl hydrolase family-13.
Although this enzyme binds a calcium ion, it is not involved in catalysis.
The literature [4] suggests that this enzyme must have a similar catalytic mechanism to that of alpha-amylase (D00165 in EzCatDB). It catalyzes the hydrolysis of (1->6)-alpha-D-glucosidic linkage.
Asp375 acts as a nucleophile, whilst Glu435 acts as general acid-base.

createdupdated
2005-03-312009-02-26


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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