DB code: D00176

RLCP classification 1.30.36000.3 : Hydrolysis
CATH domain 3.20.20.80 : TIM Barrel Catalytic domain
2.60.40.1180 : Immunoglobulin-like
E.C. 3.2.1.60
CSA 2amg
M-CSA 2amg
MACiE

CATH domain Related DB codes (homologues)
2.60.40.1180 : Immunoglobulin-like M00113 T00307 D00165 D00664 D00665 D00863 D00864 M00112 M00193 M00314 T00057 T00062 T00067
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 D00501 D00502 D00503 D00844 D00861 D00864 M00026 M00112 M00193 M00346 T00057 T00062 T00063 T00066 T00067

Uniprot Enzyme Name
UniprotKB Protein name Synonyms CAZy Pfam
P13507 Glucan 1,4-alpha-maltotetraohydrolase
G4-amylase
EC 3.2.1.60
Maltotetraose-forming amylase
Exo-maltotetraohydrolase
Maltotetraose-forming exo-amylase
CBM20 (Carbohydrate-Binding Module Family 20)
GH13 (Glycoside Hydrolase Family 13)
PF00128 (Alpha-amylase)
PF00686 (CBM_20)
PF09081 (DUF1921)
[Graphical View]

KEGG enzyme name
glucan 1,4-alpha-maltotetraohydrolase
exo-maltotetraohydrolase
1,4-alpha-D-glucan maltotetraohydrolase

UniprotKB: Accession Number Entry name Activity Subunit Subcellular location Cofactor
P13507 AMT4_PSEST Hydrolysis of (1->4)-alpha-D-glucosidic linkages in amylaceous polysaccharides, to remove successive maltotetraose residues from the non-reducing chain ends. Monomer. Secreted. Binds 2 calcium ions per subunit.

KEGG Pathways
Map code Pathways E.C.

Compound table
Cofactors Substrates Products Intermediates
KEGG-id C00076 C00657 C00001 C02052 C01935
E.C.
Compound Calcium Amylaceous polysaccharide H2O Maltotetraose Maltodextrin
Type divalent metal (Ca2+, Mg2+) polysaccharide H2O polysaccharide polysaccharide
ChEBI 29108
 29108
 		15377
 15377
PubChem 271
 271
 		22247451
 962
 22247451
 962
 		439639
 439639
1amgA01 Bound:2x_CA Unbound Unbound Unbound
1gcyA01 Bound:2x_CA Unbound Unbound Unbound
1jdaA01 Bound:2x_CA Unbound Unbound Unbound
1jdcA01 Bound:2x_CA Unbound Bound:GLC-GLC-GLC-GLC Unbound
1jddA01 Bound:2x_CA Unbound Bound:GLC-GLC-GLC-GLC Unbound
1qi3A01 Bound:2x_CA Unbound Bound:MTT Unbound
1qi4A01 Bound:2x_CA Unbound Bound:MTT Unbound
1qi5A01 Bound:2x_CA Unbound Bound:MTT Unbound
1qpkA01 Bound:2x_CA Unbound Bound:MTT Unbound
2amgA01 Bound:2x_CA Unbound Unbound Unbound
1amgA02 Unbound Unbound Unbound Unbound
1gcyA02 Unbound Unbound Unbound Unbound
1jdaA02 Unbound Unbound Unbound Unbound
1jdcA02 Unbound Unbound Unbound Unbound
1jddA02 Unbound Unbound Unbound Unbound
1qi3A02 Unbound Unbound Unbound Unbound
1qi4A02 Unbound Unbound Unbound Unbound
1qi5A02 Unbound Unbound Unbound Unbound
1qpkA02 Unbound Unbound Unbound Unbound
2amgA02 Unbound Unbound Unbound Unbound

Reference for Active-site residues
resource references E.C.
Swiss-prot;P13507 & Literature [5], [6], [8]

Active-site residues
PDB Catalytic residues Cofactor-binding residues Modified residues Main-chain involved in catalysis Comment
1amgA01 ASP 193;GLU 219;ASP 294 ASN 116;ASP 151;ASP 154;ASP 162;GLY 197(calcium-1);ASP 1;GLN 2;HIS 13;ASP 16;GLU 17(calcium-2)
1gcyA01 ASP 193;GLU 219;ASP 294 ASN 116;ASP 151;ASP 154;ASP 162;GLY 197(calcium-1);ASP 1;GLN 2;HIS 13;ASP 16;GLU 17(calcium-2)
1jdaA01 ASP 193;;ASP 294 ASN 116;ASP 151;ASP 154;ASP 162;GLY 197(calcium-1);ASP 1;GLN 2;HIS 13;ASP 16;GLU 17(calcium-2) mutant E219Q
1jdcA01 ASP 193;;ASP 294 ASN 116;ASP 151;ASP 154;ASP 162;GLY 197(calcium-1);ASP 1;GLN 2;HIS 13;ASP 16;GLU 17(calcium-2) mutant E219Q
1jddA01 ASP 193;;ASP 294 ASN 116;ASP 151;ASP 154;ASP 162;GLY 197(calcium-1);ASP 1;GLN 2;HIS 13;ASP 16;GLU 17(calcium-2) mutant E219Q
1qi3A01 ;GLU 219;ASP 294 ASN 116;ASP 151;ASP 154;ASP 162;GLY 197(calcium-1);ASP 1;GLN 2;HIS 13;ASP 16;GLU 17(calcium-2) mutant D193N
1qi4A01 ASP 193;;ASP 294 ASN 116;ASP 151;ASP 154;ASP 162;GLY 197(calcium-1);ASP 1;GLN 2;HIS 13;ASP 16;GLU 17(calcium-2) mutant E219G
1qi5A01 ASP 193;GLU 219; ASN 116;ASP 151;ASP 154;ASP 162;GLY 197(calcium-1);ASP 1;GLN 2;HIS 13;ASP 16;GLU 17(calcium-2) mutant D294N
1qpkA01 ;GLU 219;ASP 294 ASN 116;ASP 151;ASP 154;ASP 162;GLY 197(calcium-1);ASP 1;GLN 2;HIS 13;ASP 16;GLU 17(calcium-2) mutant D193G
2amgA01 ASP 193;GLU 219;ASP 294 ASN 116;ASP 151;ASP 154;ASP 162;GLY 197(calcium-1);ASP 1;GLN 2;HIS 13;ASP 16;GLU 17(calcium-2)
1amgA02
1gcyA02
1jdaA02
1jdcA02
1jddA02
1qi3A02
1qi4A02
1qi5A02
1qpkA02
2amgA02

References for Catalytic Mechanism
References Sections No. of steps in catalysis
[6]
p.625
[8]
Fig.3, p.822-823

References
[1]
Resource
Comments NUCLEOTIDE SEQUENCE
Medline ID
PubMed ID 2676600
Journal FEBS Lett
Year 1989
Volume 255
Pages 37-41
Authors Zhou JH, Baba T, Takano T, Kobayashi S, Arai Y
Title Nucleotide sequence of the maltotetraohydrolase gene from Pseudomonas saccharophila.
Related PDB
Related UniProtKB
[2]
Resource
Comments NUCLEOTIDE SEQUENCE
Medline ID
PubMed ID 2646279
Journal J Bacteriol
Year 1989
Volume 171
Pages 1333-9
Authors Fujita M, Torigoe K, Nakada T, Tsusaki K, Kubota M, Sakai S, Tsujisaka Y
Title Cloning and nucleotide sequence of the gene (amyP) for maltotetraose-forming amylase from Pseudomonas stutzeri MO-19.
Related PDB
Related UniProtKB P13507
[3]
Resource
Comments
Medline ID
PubMed ID 1368535
Journal Agric Biol Chem
Year 1990
Volume 54
Pages 737-43
Authors Nakada T, Kubota M, Sakai S, Tsujisaka Y
Title Purification and characterization of two forms of maltotetraose-forming amylase from Pseudomonas stutzeri.
Related PDB
Related UniProtKB
[4]
Resource
Comments
Medline ID
PubMed ID 1596923
Journal Carbohydr Res
Year 1992
Volume 223
Pages 255-61
Authors Zhou JH, Baba T, Takano T, Kobayashi S, Arai Y
Title Properties of the enzyme expressed by the Pseudomonas saccharophila maltotetraohydrolase gene (mta) in Escherichia coli.
Related PDB
Related UniProtKB
[5]
Resource
Comments X-RAY CRYSTALLOGRAPHY (2.0 ANGSTROMS), AND REVISIONS TO 286-302.
Medline ID 97271999
PubMed ID 9126844
Journal J Mol Biol
Year 1997
Volume 267
Pages 661-72
Authors Morishita Y, Hasegawa K, Matsuura Y, Katsube Y, Kubota M, Sakai S
Title Crystal structure of a maltotetraose-forming exo-amylase from Pseudomonas stutzeri.
Related PDB 1amg
Related UniProtKB P13507
[6]
Resource
Comments X-RAY CRYSTALLOGRAPHY (1.9 ANGSTROMS) OF VARIANT GLN-240.
Medline ID 97428332
PubMed ID 9281429
Journal J Mol Biol
Year 1997
Volume 271
Pages 619-28
Authors Yoshioka Y, Hasegawa K, Matsuura Y, Katsube Y, Kubota M
Title Crystal structures of a mutant maltotetraose-forming exo-amylase cocrystallized with maltopentaose.
Related PDB 1jda 1jdc 1jdd
Related UniProtKB P13507
[7]
Resource
Comments
Medline ID
PubMed ID 9827329
Journal Extremophiles
Year 1998
Volume 2
Pages 401-7
Authors Kobayashi H, Takaki Y, Kobata K, Takami H, Inoue A
Title Characterization of alpha-maltotetraohydrolase produced by Pseudomonas sp. MS300 isolated from the deepest site of the mariana trench.
Related PDB
Related UniProtKB
[8]
Resource
Comments X-RAY CRYSTALLOGRAPHY (2.0 ANGSTROMS) OF VARIANTS.
Medline ID 20027472
PubMed ID 10556241
Journal Protein Eng
Year 1999
Volume 12
Pages 819-24
Authors Hasegawa K, Kubota M, Matsuura Y
Title Roles of catalytic residues in alpha-amylases as evidenced by the structures of the product-complexed mutants of a maltotetraose-forming amylase.
Related PDB 1qi3 1qi4 1qi5 1qpk
Related UniProtKB P13507
[9]
Resource
Comments X-ray crystallography
Medline ID
PubMed ID 11272837
Journal Biosci Biotechnol Biochem
Year 2001
Volume 65
Pages 222-5
Authors Mezaki Y, Katsuya Y, Kubota M, Matsuura Y
Title Crystallization and structural analysis of intact maltotetraose-forming exo-amylase from Pseudomonas stutzeri.
Related PDB 1gcy
Related UniProtKB

Comments
This enzyme belongs to the glycosyl hydrolase family-13, along with alpha-amylase (D00165 in EzCatDB).
Although this enzyme binds two calcium ions, they are not involved in catalysis.
Since this enzyme has got a similar catalytic site to that of alpha-amylase (D00165 in EzCatDB), it must have a similar catalytic mechanism.

Created Updated
2004-05-10 2009-02-26