EzCatDB: S00533
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DB codeS00533
RLCP classification1.30.36211.1000 : Hydrolysis
CATH domainDomain 12.60.120.180 : Jelly RollsCatalytic domain
E.C.3.2.1.4

CATH domainRelated DB codes (homologues)
2.60.120.180 : Jelly RollsS00150,S00151,D00504,D00538

Enzyme Name
UniProtKBKEGG

O74705
Protein name
cellulase
endo-1,4-beta-D-glucanase
beta-1,4-glucanase
beta-1,4-endoglucan hydrolase
celluase A
cellulosin AP
endoglucanase D
alkali cellulase
cellulase A 3
celludextrinase
9.5 cellulase
avicelase
pancellase SS
1,4-(1,3
1,4)-beta-D-glucan 4-glucanohydrolase
SynonymsEndoglucanase A
EC 3.2.1.4
PfamPF01670 (Glyco_hydro_12)
[Graphical view]
CAZyGH12 (Glycoside Hydrolase Family)

KEGG pathways
MAP codePathways
MAP00500Starch and sucrose metabolism

UniProtKB:Accession NumberO74705
Entry nameO74705_ASPNG
Activity
Subunit
Subcellular location
Cofactor

Compound table: links to PDB-related databases & PoSSuM

SubstratesProductsintermediates
KEGG-idC00760C00478C00551C00001C00760C00551

CompoundCelluloseLicheninbeta-D-GlucanH2OCellulosebeta-D-GlucanTransition-state for glycosylated enzymeGlycosylated enzyme intermediate
TypepolysaccharidecarbohydratepolysaccharideH2Opolysaccharidepolysaccharide

ChEBI


15377




PubChem
439241
46173706
962
22247451

46173706


                
1ks4AUnboundUnboundUnbound UnboundUnbound  
1ks5AUnboundUnboundUnbound UnboundUnbound  

Active-site residues
resource
PDB;1h8v, literature [2], [4]
pdbCatalytic residues
         
1ks4AASP  95;ASP  99;GLU 116;GLU 204
1ks5AASP  95;ASP  99;GLU 116;GLU 204

References for Catalytic Mechanism
ReferencesSectionsNo. of steps in catalysis
[1]p.663-664

references
[1]
CommentsX-RAY CRYSTALLOGRAPHY (2.1 ANGSTROMS) OF 17-239.
PubMed ID11914491
JournalActa Crystallogr D Biol Crystallogr
Year2002
Volume58
Pages660-7
AuthorsKhademi S, Zhang D, Swanson SM, Wartenberg A, Witte K, Meyer EF
TitleDetermination of the structure of an endoglucanase from Aspergillus niger and its mode of inhibition by palladium chloride.
Related PDB1ks4,1ks5
Related UniProtKBO74705

comments
This family belongs to glycosidase family-12, which has a retaining mechanism.
The catalytic domain of this enzyme is homologous to those of another cellulase (S00150 in EzCatDB) and beta-1,4-Glucanase (D00504 in EzCatDB), whose catalytic mechanisms must be similar to that of this enzyme.
According to the literature [1], the catalytic reaction proceeds as follows:
(1) Asp95 may modulate the activity of Glu204 as a acid-base.
(2) Glu204 acts as a general acid to protonate the leaving oxygen atom, leading to a oxocarbenium-like transtion state from cellulose substrate.
(3) pKa of Glu116, which acts as a nucleophile, is modulated by Asp99.
(4) Glu116 makes a nucleophilic attack on C1 atom of the transition state, forming a glycosyl-enzyme intermediate.
(5) Glu204 acts as a general base to activate a water molecule.
(6) The activated water makes a nucleophilic attack on the C1 atom of the intermediate. This reaction proceeds through an oxocarbenium-like transition state to complete the hydrolysis.

createdupdated
2004-05-172009-02-26


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 2008)
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)
Funded by Grant-in-Aid for Publication of Scientific Research Results/Japan Society for the Promotion of Science (JSPS) (April 2012 - March 2013)
Supported by the commission for the Development of Artificial Gene Synthesis Technology for Creating Innovative Biomaterial from the Ministry of Economy, Trade and Industry (METI) (October 2012 - )
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