DB code: S00203

RLCP classification 1.30.35885.972 : Hydrolysis
CATH domain 3.20.20.80 : TIM Barrel Catalytic domain
E.C. 3.2.1.4
CSA
M-CSA
MACiE

CATH domain Related DB codes (homologues)
3.20.20.80 : TIM Barrel S00202 S00210 S00748 S00906 S00907 S00911 S00912 S00915 M00134 M00160 D00479 S00204 S00205 S00206 S00207 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

Uniprot Enzyme Name
UniprotKB Protein name Synonyms RefSeq CAZy Pfam
A3DJ77 Endoglucanase C
EgC
EC 3.2.1.4
Endo-1,4-beta-glucanase C
Cellulase C
YP_001039199.1 (Protein)
NC_009012.1 (DNA/RNA sequence)
GH5 (Glycoside Hydrolase Family 5)
PF00150 (Cellulase)
[Graphical View]

KEGG enzyme 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

UniprotKB: Accession Number Entry name Activity Subunit Subcellular location Cofactor
A3DJ77 GUNC_CLOTH Endohydrolysis of (1->4)-beta-D-glucosidic linkages in cellulose, lichenin and cereal beta-D-glucans.

KEGG Pathways
Map code Pathways E.C.
MAP00500 Starch and sucrose metabolism

Compound table
Substrates Products Intermediates
KEGG-id C00760 C00001 C00478 C00551 C00760 C00551 C00185 I00120
E.C.
Compound Cellulose H2O Lichenin beta-D-Glucan Cellulose beta-D-Glucan Cellobiose Peptidyl-Glu-cellulose
Type polysaccharide H2O carbohydrate polysaccharide polysaccharide polysaccharide polysaccharide
ChEBI 15377
17057
PubChem 22247451
962
439241
46173706
46173706
439178
1cecA Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Unbound Unbound Unbound Unbound Unbound Unbound
1cenA Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Unbound Unbound Bound:BGC-GLC Unbound Unbound Unbound
1ceoA Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Unbound Unbound Unbound Unbound Unbound Unbound

Reference for Active-site residues
resource references E.C.

Active-site residues
PDB Catalytic residues Cofactor-binding residues Modified residues Main-chain involved in catalysis Comment
1cecA Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain ARG 46;ASN 139;GLU 140;HIS 198;TYR 200;GLU 280
1cenA Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain ARG 46;ASN 139;;HIS 198;TYR 200;GLU 280 mutant E140Q
1ceoA Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain ARG 46;ASN 139;;HIS 198;TYR 200;GLU 280 mutant E140Q

References for Catalytic Mechanism
References Sections No. of steps in catalysis
[3]
p.10656-10657, Fig.9 4
[6]
Fig.3 4
[7]
Fig.1, Fig.2 4

References
[1]
Resource
Comments X-ray crystallography (2.15 Angstroms)
Medline ID 95393242
PubMed ID 7664125
Journal Nat Struct Biol
Year 1995
Volume 2
Pages 569-76
Authors Dominguez R, Souchon H, Spinelli S, Dauter Z, Wilson KS, Chauvaux S, Beguin P, Alzari PM
Title A common protein fold and similar active site in two distinct families of beta-glycanases.
Related PDB 1cec
Related UniProtKB P07985
[2]
Resource
Comments X-ray crystallography (1.64 Angstroms) of 27-406
Medline ID 96097400
PubMed ID 8535787
Journal Structure
Year 1995
Volume 3
Pages 939-49
Authors Ducros V, Czjzek M, Belaich A, Gaudin C, Fierobe HP, Belaich JP, Davies GJ, Haser R
Title Crystal structure of the catalytic domain of a bacterial cellulase belonging to family 5.
Related PDB 1edg
Related UniProtKB P17901
[3]
Resource
Comments X-ray crystallography (2.4 Angstroms)
Medline ID 96346058
PubMed ID 8718854
Journal Biochemistry
Year 1996
Volume 35
Pages 10648-60
Authors Sakon,J. , Adney,W S. , Himmel,M E. , Thomas,S R. , Karplus,P A
Title Crystal structure of thermostable family 5 endocellulase E1 from Acidothermus cellulolyticus in complex with cellotetraose.
Related PDB 1ece
Related UniProtKB P54583
[4]
Resource
Comments X-ray crystallography (2.3 Angstroms) of mutant GLN-140.
Medline ID 96192088
PubMed ID 8632467
Journal J Mol Biol
Year 1996
Volume 257
Pages 1042-51
Authors Dominguez R, Souchon H, Lascombe M, Alzari PM
Title The crystal structure of a family 5 endoglucanase mutant in complexed and uncomplexed forms reveals an induced fit activation mechanism.
Related PDB 1cen 1ceo
Related UniProtKB P07985
[5]
Resource
Comments structure by NMR of 365-426
Medline ID 98070232
PubMed ID 9405041
Journal Biochemistry
Year 1997
Volume 36
Pages 16074-86
Authors Brun E, Moriaud F, Gans P, Blackledge MJ, Barras F, Marion D
Title Solution structure of the cellulose-binding domain of the endoglucanase Z secreted by Erwinia chrysanthemi.
Related PDB
Related UniProtKB P07103
[6]
Resource
Comments X-ray crystallography (1.57 Angstroms) of 30-329
Medline ID 98153671
PubMed ID 9485319
Journal Biochemistry
Year 1998
Volume 37
Pages 1926-32
Authors Davies GJ, Dauter M, Brzozowski AM, Bjornvad ME, Andersen KV, Schulein M
Title Structure of the Bacillus agaradherans family 5 endoglucanase at 1.6 A and its cellobiose complex at 2.0 A resolution.
Related PDB 1a3h 2a3h
Related UniProtKB O85465
[7]
Resource
Comments X-ray crystallography (1.64 Angstroms) of 30-329
Medline ID 98384136
PubMed ID 9718293
Journal Biochemistry
Year 1998
Volume 37
Pages 11707-13
Authors Davies GJ, Mackenzie L, Varrot A, Dauter M, Brzozowski AM, Schulein M, Withers SG
Title Snapshots along an enzymatic reaction coordinate: analysis of a retaining beta-glycoside hydrolase.
Related PDB 3a3h 4a3h 5a3h 6a3h 7a3h
Related UniProtKB O85465
[8]
Resource
Comments X-ray crystallography (1.75/1.95/2.1 Angstroms)
Medline ID
PubMed ID 10731432
Journal J Mol Biol
Year 2000
Volume 297
Pages 819-28
Authors Varrot A, Schulein M, Davies GJ
Title Insights into ligand-induced conformational change in Cel5A from Bacillus agaradhaerens revealed by a catalytically active crystal form.
Related PDB 1qhz 1qi0 1qi2
Related UniProtKB
[9]
Resource
Comments X-ray crystallography (2.3 Angstroms) of 44-335
Medline ID 21392910
PubMed ID 11501995
Journal J Mol Biol
Year 2001
Volume 310
Pages 1055-66
Authors Chapon V, Czjzek M, El Hassouni M, Py B, Juy M, Barras F
Title Type II protein secretion in gram-negative pathogenic bacteria: the study of the structure/secretion relationships of the cellulase Cel5 (formerly EGZ) from Erwinia chrysanthemi.
Related PDB
Related UniProtKB P07103
[10]
Resource
Comments X-ray crystallography, catalysis
Medline ID
PubMed ID 12079387
Journal J Mol Biol
Year 2002
Volume 320
Pages 303-9
Authors Shaw A, Bott R, Vonrhein C, Bricogne G, Power S, Day AG
Title A novel combination of two classic catalytic schemes.
Related PDB
Related UniProtKB

Comments
This family belongs to glycosidase family-5, which has an retaining mechanism (equatorial to equatorial conformation), and also a family of 4/7 superfamily, which has got catalytic residues at the C-terminal ends of beta-4 and beta-7 on the (alpha/beta)8 barrel fold.
This enzyme must have the same catalytic mechanism as that of the other TIM barrel cellulases (D00501, D00502 & D00503 in EzCatDB).
According to the literature [3], Glu282 and Glu162 (of 1ece from D00502 in EzCatDB) act as a nucleophile and acid-base, respectively. The catalysis proceeds through a dissociative-type (or SN1-like) mechanism, with a formation of oxocarbonium ion in the transition state, during the glycosylation of the active site. During the glycosylation, Glu282 approaches the C1 atom of the glcose, whilst Glu162 protonates the leaving group. At the second stage, or during the deglycosylation, a water molecule can be activated by a general base, Glu162. This deglycosylation also goes through the dissociative-type reaction with an oxocarbonium ion in the transition state, in which water replaced the glycosyl leaving group in the first step.
Moreover, comparing the structural data with that of xylanase (E.C. 3.2.1.8) (D00479 in EzCatDB), Tyr240 (of 1ece) might stabilize the leaving nucleophile, Glu282 in deglycosylation, whilst His238 might modulate the activity of Glu162 (see [3]). On the other hand, Tyr240 might modulate the activity of the nucleophile, according to the data of the other homologous enzyme, beta-glucosidase (E.C. 3.2.1.21) (S00205 in EzCatDB).

Created Updated
2002-10-18 2012-02-14