DB code: S00150

RLCP classification	1.30.36211.992 : Hydrolysis
CATH domain	2.60.120.180 : Jelly Rolls	Catalytic domain
E.C.	3.2.1.4
CSA
M-CSA
MACiE

CATH domain	Related DB codes (homologues)
2.60.120.180 : Jelly Rolls	S00533 S00151 D00504 D00538

Uniprot Enzyme Name
UniprotKB	Protein name	Synonyms	CAZy	Pfam
O33897		Cellulase EC 3.2.1.4	GH12 (Glycoside Hydrolase Family 12)	PF01670 (Glyco_hydro_12) [Graphical View]
O00095		Endo-beta-1,4-glucanase (Beta-1,4-glucanase) EC 3.2.1.4	GH12 (Glycoside Hydrolase Family 12)	PF01670 (Glyco_hydro_12) [Graphical View]
Q8NJY3		Endoglucanase	GH12 (Glycoside Hydrolase Family 12)	PF01670 (Glyco_hydro_12) [Graphical View]
Q8NJY6		Endoglucanase	GH12 (Glycoside Hydrolase Family 12)	PF01670 (Glyco_hydro_12) [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
O33897	O33897_RHOMR
O00095	O00095_TRIRE
Q8NJY3	Q8NJY3_9ASCO
Q8NJY6	Q8NJY6_9HYPO

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

Compound table
	Substrates				Products		Intermediates
KEGG-id	C00760	C00478	C00551	C00001	C00760	C00551
E.C.
Compound	Cellulose	Lichenin	beta-D-Glucan	H2O	Cellulose	beta-D-Glucan	Transition-state for glycosylated enzyme	Glycosylated enzyme intermediate
Type	polysaccharide	carbohydrate	polysaccharide	H2O	polysaccharide	polysaccharide
ChEBI				15377 15377
PubChem		439241 439241	46173706 46173706	22247451 962 22247451 962		46173706 46173706

1h0bA	Unbound	Unbound	Unbound		Unbound	Unbound
1h0bB	Unbound	Unbound	Unbound		Unbound	Unbound
2bw8A	Unbound	Unbound	Unbound		Unbound	Unbound
2bw8B	Unbound	Unbound	Unbound		Unbound	Unbound
2bwaA	Unbound	Unbound	Unbound		Bound:GLC-BGC-BGC	Unbound
2bwaB	Unbound	Unbound	Unbound		Bound:GLC-BGC	Unbound
2bwcA	Unbound	Unbound	Unbound		Bound:GLC-BGC-BGC	Unbound
2bwcB	Bound:GLC-BGC-BGC-BGC	Unbound	Unbound		Bound:BGC-BGC-BGC	Unbound
1h8vA	Unbound	Unbound	Unbound		Unbound	Unbound
1h8vB	Unbound	Unbound	Unbound		Unbound	Unbound
1h8vC	Unbound	Unbound	Unbound		Unbound	Unbound
1h8vD	Unbound	Unbound	Unbound		Unbound	Unbound
1h8vE	Unbound	Unbound	Unbound		Unbound	Unbound
1h8vF	Unbound	Unbound	Unbound		Unbound	Unbound
1oa2A	Unbound	Unbound	Unbound		Unbound	Unbound
1oa2B	Unbound	Unbound	Unbound		Unbound	Unbound
1oa2C	Unbound	Unbound	Unbound		Unbound	Unbound
1oa2D	Unbound	Unbound	Unbound		Unbound	Unbound
1oa2E	Unbound	Unbound	Unbound		Unbound	Unbound
1oa2F	Unbound	Unbound	Unbound		Unbound	Unbound
1olqA	Unbound	Unbound	Unbound		Unbound	Unbound
1olqB	Unbound	Unbound	Unbound		Unbound	Unbound
1olrA	Unbound	Unbound	Unbound		Unbound	Unbound
1uu4A	Unbound	Unbound	Unbound		Unbound	Bound:BGC-BGC
1uu5A	Unbound	Unbound	Unbound		Bound:BGC-BGC-BGC-BGC	Unbound
1uu6A	Bound:BGC-BGC-BGC-BGC	Unbound	Unbound		Unbound	Unbound
1w2uA	Bound:BGC-BGC-BGC-BGC	Unbound	Unbound		Unbound	Unbound
1oa3A	Unbound	Unbound	Unbound		Unbound	Unbound
1oa3B	Unbound	Unbound	Unbound		Unbound	Unbound
1oa3C	Unbound	Unbound	Unbound		Unbound	Unbound
1oa3D	Unbound	Unbound	Unbound		Unbound	Unbound

Reference for Active-site residues
resource	references	E.C.
literature [2], [3], [5], [7]

Active-site residues
PDB	Catalytic residues	Cofactor-binding residues	Modified residues	Main-chain involved in catalysis	Comment

1h0bA	ASN 102;ASP 106;GLU 124;GLU 207
1h0bB	ASN 102;ASP 106;GLU 124;GLU 207
2bw8A	ASN 102;ASP 106;GLU 124;GLU 207
2bw8B	ASN 102;ASP 106;GLU 124;GLU 207
2bwaA	ASN 102;ASP 106;GLU 124;GLU 207
2bwaB	ASN 102;ASP 106;GLU 124;GLU 207
2bwcA	ASN 102;ASP 106;GLU 124;GLU 207
2bwcB	ASN 102;ASP 106;GLU 124;GLU 207
1h8vA	ASN 95;ASP 99;GLU 116;GLU 200
1h8vB	ASN 95;ASP 99;GLU 116;GLU 200
1h8vC	ASN 95;ASP 99;GLU 116;GLU 200
1h8vD	ASN 95;ASP 99;GLU 116;GLU 200
1h8vE	ASN 95;ASP 99;GLU 116;GLU 200
1h8vF	ASN 95;ASP 99;GLU 116;GLU 200
1oa2A	ASN 95;ASP 99;GLU 116;GLU 200
1oa2B	ASN 95;ASP 99;GLU 116;GLU 200
1oa2C	ASN 95;ASP 99;GLU 116;GLU 200
1oa2D	ASN 95;ASP 99;GLU 116;GLU 200
1oa2E	ASN 95;ASP 99;GLU 116;GLU 200
1oa2F	ASN 95;ASP 99;GLU 116;GLU 200
1olqA	ASN 95;ASP 99;GLU 116;GLU 200
1olqB	ASN 95;ASP 99;GLU 116;GLU 200
1olrA	ASN 99;ASP 103;GLU 120;GLU 205
1uu4A	ASN 99;ASP 103;GLU 120;GLU 205
1uu5A	ASN 99;ASP 103;GLU 120;GLU 205
1uu6A	ASN 99;ASP 103;GLU 120;GLU 205
1w2uA	ASN 99;ASP 103;GLU 120;GLU 205
1oa3A	ASN 95;ASP 99;GLU 116;GLU 200
1oa3B	ASN 95;ASP 99;GLU 116;GLU 200
1oa3C	ASN 95;ASP 99;GLU 116;GLU 200
1oa3D	ASN 95;ASP 99;GLU 116;GLU 200

References for Catalytic Mechanism
References	Sections	No. of steps in catalysis
[2]	p.16037-16038
[3]	Scheme 1, p.139-140
[4]	p.301
[6]	p.888-889
[9]	p.1510-1511
[11]	Fig.2, p.252-254
[12]	p.63-64, p.67

References
[1]
Resource
Comments
Medline ID
PubMed ID	8477842
Journal	FEBS Lett
Year	1993
Volume	321
Pages	135-9
Authors	Torronen A, Kubicek CP, Henrissat B
Title	Amino acid sequence similarities between low molecular weight endo-1,4-beta-xylanases and family H cellulases revealed by clustering analysis.
Related PDB
Related UniProtKB
[2]
Resource
Comments
Medline ID
PubMed ID	9440876
Journal	Biochemistry
Year	1997
Volume	36
Pages	16032-9
Authors	Sulzenbacher G, Shareck F, Morosoli R, Dupont C, Davies GJ
Title	The Streptomyces lividans family 12 endoglucanase: construction of the catalytic cre, expression, and X-ray structure at 1.75 A resolution.
Related PDB
Related UniProtKB
[3]
Resource
Comments
Medline ID
PubMed ID	9806895
Journal	Biochem J
Year	1998
Volume	336
Pages	139-45
Authors	Zechel DL, He S, Dupont C, Withers SG
Title	Identification of Glu-120 as the catalytic nucleophile in Streptomyces lividans endoglucanase celB.
Related PDB
Related UniProtKB
[4]
Resource
Comments	X-RAY CRYSTALLOGRAPHY (1.9 ANGSTROMS) OF 17-234.
Medline ID
PubMed ID	11327768
Journal	J Mol Biol
Year	2001
Volume	308
Pages	295-310
Authors	Sandgren M, Shaw A, Ropp TH, Wu S, Bott R, Cameron AD, Stahlberg J, Mitchinson C, Jones TA
Title	The X-ray crystal structure of the Trichoderma reesei family 12 endoglucanase 3, Cel12A, at 1.9 A resolution.
Related PDB	1h8v
Related UniProtKB	O00095
[5]
Resource
Comments
Medline ID
PubMed ID	12073090
Journal	Curr Genet
Year	2002
Volume	41
Pages	89-98
Authors	Goedegebuur F, Fowler T, Phillips J, van der Kley P, van Solingen P, Dankmeyer L, Power SD
Title	Cloning and relational analysis of 15 novel fungal endoglucanases from family 12 glycosyl hydrolase.
Related PDB
Related UniProtKB
[6]
Resource
Comments	X-RAY CRYSTALLOGRAPHY (1.8 ANGSTROMS) OF 38-260.
Medline ID
PubMed ID	12095262
Journal	J Mol Biol
Year	2002
Volume	320
Pages	883-97
Authors	Crennell SJ, Hreggvidsson GO, Nordberg Karlsson E
Title	The structure of Rhodothermus marinus Cel12A, a highly thermostable family 12 endoglucanase, at 1.8 A resolution.
Related PDB	1h0b
Related UniProtKB	O33897
[7]
Resource
Comments	X-RAY CRYSTALLOGRAPHY (1.7 ANGSTROMS) OF 17-234.
Medline ID
PubMed ID	14627738
Journal	Protein Sci
Year	2003
Volume	12
Pages	2782-93
Authors	Sandgren M, Gualfetti PJ, Paech C, Paech S, Shaw A, Gross LS, Saldajeno M, Berglund GI, Jones TA, Mitchinson C
Title	The Humicola grisea Cel12A enzyme structure at 1.2 A resolution and the impact of its free cysteine residues on thermal stability.
Related PDB	1olr 1olq
Related UniProtKB	O00095 Q8NJY3
[8]
Resource
Comments	X-RAY CRYSTALLOGRAPHY (1.5 ANGSTROMS) OF 17-234.
Medline ID
PubMed ID	12649442
Journal	Protein Sci
Year	2003
Volume	12
Pages	848-60
Authors	Sandgren M, Gualfetti PJ, Shaw A, Gross LS, Saldajeno M, Day AG, Jones TA, Mitchinson C
Title	Comparison of family 12 glycoside hydrolases and recruited substitutions important for thermal stability.
Related PDB	1oa2 1oa3
Related UniProtKB	O00095
[9]
Resource
Comments	X-RAY CRYSTALLOGRAPHY (1.49 ANGSTROMS) OF 31-254.
Medline ID
PubMed ID	15364577
Journal	J Mol Biol
Year	2004
Volume	342
Pages	1505-17
Authors	Sandgren M, Berglund GI, Shaw A, Stahlberg J, Kenne L, Desmet T, Mitchinson C
Title	Crystal complex structures reveal how substrate is bound in the -4 to the +2 binding sites of Humicola grisea Cel12A.
Related PDB	1uu4 1uu5 1uu6 1w2u
Related UniProtKB	Q8NJY3 Q8NJY6
[10]
Resource
Comments
Medline ID
PubMed ID	15456402
Journal	Biochem J
Year	2005
Volume	385
Pages	581-8
Authors	Huang Y, Krauss G, Cottaz S, Driguez H, Lipps G
Title	A highly acid-stable and thermostable endo-beta-glucanase from the thermoacidophilic archaeon Sulfolobus solfataricus.
Related PDB
Related UniProtKB
[11]
Resource
Comments
Medline ID
PubMed ID	15950056
Journal	Prog Biophys Mol Biol
Year	2005
Volume	89
Pages	246-91
Authors	Sandgren M, Stahlberg J, Mitchinson C
Title	Structural and biochemical studies of GH family 12 cellulases: improved thermal stability, and ligand complexes.
Related PDB
Related UniProtKB
[12]
Resource
Comments	X-ray crystallography
Medline ID
PubMed ID	16343530
Journal	J Mol Biol
Year	2006
Volume	356
Pages	57-71
Authors	Crennell SJ, Cook D, Minns A, Svergun D, Andersen RL, Nordberg Karlsson E
Title	Dimerisation and an increase in active site aromatic groups as adaptations to high temperatures: X-ray solution scattering and substrate-bound crystal structures of Rhodothermus marinus endoglucanase Cel12A.
Related PDB	2bw8 2bwa 2bwc
Related UniProtKB

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 (S00533 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 [2], [3] & [7], the catalytic reaction proceeds as follows: (1) Asn102 (of 1h0b) may modulate the activity of Glu207 as a acid-base. (2) Glu207 (of 1h0b) acts as a general acid to protonate the leaving oxygen atom, leading to a oxocarbenium-like transtion state from cellulose substrate. (3) pKa of Glu124 (of 1h0b), which acts as a nucleophile, is modulated by Asp106. (4) Glu124 makes a nucleophilic attack on C1 atom of the transition state, forming a glycosyl-enzyme intermediate. (5) Glu207 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.

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 (S00533 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 [2], [3] & [7], the catalytic reaction proceeds as follows:
(1) Asn102 (of 1h0b) may modulate the activity of Glu207 as a acid-base.
(2) Glu207 (of 1h0b) acts as a general acid to protonate the leaving oxygen atom, leading to a oxocarbenium-like transtion state from cellulose substrate.
(3) pKa of Glu124 (of 1h0b), which acts as a nucleophile, is modulated by Asp106.
(4) Glu124 makes a nucleophilic attack on C1 atom of the transition state, forming a glycosyl-enzyme intermediate.
(5) Glu207 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.

Created	Updated
2004-05-17	2009-02-26