DB code: T00067

RLCP classification 1.30.36000.3 : Hydrolysis
CATH domain 2.60.40.10 : Immunoglobulin-like
3.20.20.80 : TIM Barrel Catalytic domain
2.60.40.1180 : Immunoglobulin-like
E.C. 3.2.1.68
CSA 1bf2
M-CSA 1bf2
MACiE

CATH domain Related DB codes (homologues)
2.60.40.10 : Immunoglobulin-like M00131 T00257 T00005 M00113 M00127 M00132 M00323 M00325 M00327 M00329 M00330 M00331 M00332 T00307 D00166 D00500 M00112 M00193 T00063 T00065 T00245
2.60.40.1180 : Immunoglobulin-like M00113 T00307 D00165 D00176 D00664 D00665 D00863 D00864 M00112 M00193 M00314 T00057 T00062
3.20.20.80 : TIM Barrel S00202 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

Uniprot Enzyme Name
UniprotKB Protein name Synonyms CAZy Pfam
P10342 Isoamylase
EC 3.2.1.68
CBM48 (Carbohydrate-Binding Module Family 48)
GH13 (Glycoside Hydrolase Family 13)
PF00128 (Alpha-amylase)
PF02922 (CBM_48)
[Graphical View]

KEGG enzyme name
isoamylase
debranching enzyme
glycogen alpha-1,6-glucanohydrolase

UniprotKB: Accession Number Entry name Activity Subunit Subcellular location Cofactor
P10342 ISOA_PSEAY Hydrolysis of (1->6)-alpha-D-glucosidic branch linkages in glycogen, amylopectin and their beta-limit dextrins. Monomer. Binds 1 calcium ion per subunit.

KEGG Pathways
Map code Pathways E.C.

Compound table
Substrates Products Intermediates
KEGG-id C00182 C00317 C00001 C00718 C00721
E.C.
Compound Glycogen Amylopectin H2O Amylose Dextrin
Type polysaccharide polysaccharide H2O polysaccharide polysaccharide
ChEBI 28087
28057
15377
PubChem 439177
439207
962
22247451
1bf2A01 Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Unbound Unbound Unbound
1bf2A02 Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Unbound Unbound Unbound
1bf2A03 Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Unbound Unbound Unbound

Reference for Active-site residues
resource references E.C.
Swiss-prot;P10342 & literature [3]

Active-site residues
PDB Catalytic residues Cofactor-binding residues Modified residues Main-chain involved in catalysis Comment
1bf2A01 Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain
1bf2A02 Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain ASP 375;GLU 435;ASP 510
1bf2A03 Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain

References for Catalytic Mechanism
References Sections No. of steps in catalysis
[3]
p.890-892
[4]
Fig.2, p.4-5, p.11

References
[1]
Resource
Comments
Medline ID
PubMed ID 7175943
Journal J Mol Biol
Year 1982
Volume 160
Pages 669-71
Authors Sato M, Hato Y, Ii Y, Miki K, Kasai N, Tanaka N, Harada T
Title Preliminary x-ray studies on Pseudomonas isoamylase.
Related PDB
Related UniProtKB
[2]
Resource
Comments
Medline ID
PubMed ID 1388153
Journal J Biol Chem
Year 1992
Volume 267
Pages 18447-52
Authors Takata H, Kuriki T, Okada S, Takesada Y, Iizuka M, Minamiura N, Imanaka T
Title Action of neopullulanase. Neopullulanase catalyzes both hydrolysis and transglycosylation at alpha-(1----4)- and alpha-(1----6)-glucosidic linkages.
Related PDB
Related UniProtKB
[3]
Resource
Comments X-RAY CRYSTALLOGRAPHY (2.0 ANGSTROMS).
Medline ID 98387895
PubMed ID 9719642
Journal J Mol Biol
Year 1998
Volume 281
Pages 885-97
Authors Katsuya Y, Mezaki Y, Kubota M, Matsuura Y
Title Three-dimensional structure of Pseudomonas isoamylase at 2.2 A resolution.
Related PDB 1bf2
Related UniProtKB P10342
[4]
Resource
Comments
Medline ID
PubMed ID 11257505
Journal Biochim Biophys Acta
Year 2001
Volume 1546
Pages 1-20
Authors MacGregor EA, Janecek S, Svensson B
Title Relationship of sequence and structure to specificity in the alpha-amylase family of enzymes.
Related PDB
Related UniProtKB
[5]
Resource
Comments
Medline ID
PubMed ID 12509527
Journal Plant Cell
Year 2003
Volume 15
Pages 133-49
Authors Hussain H, Mant A, Seale R, Zeeman S, Hinchliffe E, Edwards A, Hylton C, Bornemann S, Smith AM, Martin C, Bustos R
Title Three isoforms of isoamylase contribute different catalytic properties for the debranching of potato glucans.
Related PDB
Related UniProtKB

Comments
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.
This enzyme belongs to the glycosyl hydrolase family-13.

Created Updated
2005-03-31 2009-02-26