DB code: S00162

RLCP classification	1.30.36210.990 : Hydrolysis
CATH domain	2.70.100.10 : 1,4-Beta-D-Glucan Cellobiohydrolase I; Chain A	Catalytic domain
E.C.	3.2.1.4
CSA
M-CSA
MACiE

CATH domain	Related DB codes (homologues)
2.70.100.10 : 1,4-Beta-D-Glucan Cellobiohydrolase I; Chain A	D00499

Uniprot Enzyme Name
UniprotKB	Protein name	Synonyms	CAZy	Pfam
P56680	Endoglucanase 1	EC 3.2.1.4 Endoglucanase I Endo-1,4-beta-glucanase 1 Cellulase 1	GH7 (Glycoside Hydrolase Family 7)	PF00840 (Glyco_hydro_7) [Graphical View]
P46237	Endoglucanase type C	EC 3.2.1.4 Endo-1,4-beta-glucanase Endoglucanase I EG I Cellulase	GH7 (Glycoside Hydrolase Family 7)	PF00840 (Glyco_hydro_7) [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
P56680	GUN1_HUMIN	Endohydrolysis of (1->4)-beta-D-glucosidic linkages in cellulose, lichenin and cereal beta-D-glucans.	Monomer.	Secreted.
P46237	GUNC_FUSOX	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	C00478	C00551	C00001	C00760	C00551
E.C.
Compound	Cellulose	Lichenin	beta-D-Glucan	H2O	Cellulose	beta-D-Glucan	Transition-state in glycosylation	Glycosyl-enzyme intermediate	Transition-state in deglycosylation
Type	polysaccharide	carbohydrate	polysaccharide	H2O	polysaccharide	polysaccharide
ChEBI				15377 15377
PubChem		439241 439241	46173706 46173706	22247451 962 22247451 962		46173706 46173706

1a39A	Unbound	Unbound	Unbound		Unbound	Unbound		Unbound
1dymA	Unbound	Unbound	Unbound		Unbound	Unbound		Unbound
1ojiA	Unbound	Unbound	Unbound		Unbound	Unbound		Unbound
1ojjA	Unbound	Unbound	Unbound		Analogue:GAL-GLC	Analogue:GAL-BGC		Unbound
1ojjB	Unbound	Unbound	Unbound		Analogue:GAL-GLC	Analogue:GAL-BGC		Unbound
1ojkA	Unbound	Unbound	Unbound		Analogue:BGC-GLC	Bound:BGC-BGC		Unbound
1ojkB	Unbound	Unbound	Unbound		Analogue:BGC-GLC	Bound:BGC-BGC		Unbound
2a39A	Unbound	Unbound	Unbound		Unbound	Unbound		Unbound
2a39B	Unbound	Unbound	Unbound		Unbound	Unbound		Unbound
1ovwA	Analogue:DP5	Unbound	Unbound		Unbound	Unbound		Unbound
1ovwB	Analogue:DP5	Unbound	Unbound		Unbound	Unbound		Unbound
1ovwC	Analogue:DP5	Unbound	Unbound		Unbound	Unbound		Unbound
1ovwD	Analogue:DP5	Unbound	Unbound		Unbound	Unbound		Unbound
2ovwA	Unbound	Unbound	Unbound		Bound:CBI	Unbound		Unbound
2ovwB	Unbound	Unbound	Unbound		Bound:CBI	Unbound		Unbound
2ovwC	Unbound	Unbound	Unbound		Bound:CBI	Unbound		Unbound
2ovwD	Unbound	Unbound	Unbound		Bound:CBI	Unbound		Unbound
3ovwA	Unbound	Unbound	Unbound		Unbound	Unbound		Unbound
3ovwB	Unbound	Unbound	Unbound		Unbound	Unbound		Unbound
4ovwA	Unbound	Unbound	Unbound		Unbound	Unbound		Intermediate-analogue:IN1
4ovwB	Unbound	Unbound	Unbound		Unbound	Unbound		Intermediate-analogue:IN1

Reference for Active-site residues
resource	references	E.C.
literature [11]

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

1a39A	GLU 197;ASP 199;GLU 202;HIS 213				mutant S37W, P39W
1dymA	;ASP 199;GLU 202;HIS 213				mutant E197A
1ojiA	;ASP 199;GLU 202;HIS 213				mutant E197S
1ojjA	;ASP 199;GLU 202;HIS 213				mutant E197S
1ojjB	;ASP 199;GLU 202;HIS 213				mutant E197S
1ojkA	;ASP 199;GLU 202;HIS 213				mutant E197S
1ojkB	;ASP 199;GLU 202;HIS 213				mutant E197S
2a39A	GLU 197;ASP 199;GLU 202;HIS 213
2a39B	GLU 197;ASP 199;GLU 202;HIS 213
1ovwA	GLU 197;ASP 199;GLU 202;HIS 213
1ovwB	GLU 197;ASP 199;GLU 202;HIS 213
1ovwC	GLU 197;ASP 199;GLU 202;HIS 213
1ovwD	GLU 197;ASP 199;GLU 202;HIS 213
2ovwA	GLU 197;ASP 199;GLU 202;HIS 213
2ovwB	GLU 197;ASP 199;GLU 202;HIS 213
2ovwC	GLU 197;ASP 199;GLU 202;HIS 213
2ovwD	GLU 197;ASP 199;GLU 202;HIS 213
3ovwA	GLU 197;ASP 199;GLU 202;HIS 213
3ovwB	GLU 197;ASP 199;GLU 202;HIS 213
4ovwA	GLU 197;ASP 199;GLU 202;HIS 213
4ovwB	GLU 197;ASP 199;GLU 202;HIS 213

References for Catalytic Mechanism
References	Sections	No. of steps in catalysis
[5]	Fig.1, Fig.7, p.15284-15285
[7]	Fig.1, p.5900
[8]	Fig.4, p.5909-5910
[11]	p.388-389
[12]	Scheme 1, p.415-416
[13]	Scheme 1, p.27
[14]	p.1101
[15]	Fig.1, p.622-624

References
[1]
Resource
Comments
Medline ID
PubMed ID
Journal	FEBS Lett
Year	1989
Volume	243
Pages	239-43
Authors	Tomme P, Clayssens M
Title	Identification of a functionally important carboxyl group in cellobiohydrolase I from Trichoderma reesei.
Related PDB
Related UniProtKB
[2]
Resource
Comments
Medline ID
PubMed ID	2396985
Journal	Biochem J
Year	1990
Volume	270
Pages	251-6
Authors	Claeyssens M, van Tilbeurgh H, Kamerling JP, Berg J, Vrsanska M, Biely P
Title	Studies of the cellulolytic system of the filamentous fungus Trichoderma reesei QM 9414. Substrate specificity and transfer activity of endoglucanase I.
Related PDB
Related UniProtKB
[3]
Resource
Comments
Medline ID
PubMed ID	2261982
Journal	FEBS Lett
Year	1990
Volume	275
Pages	135-8
Authors	Mitsuishi Y, Nitisinprasert S, Saloheimo M, Biese I, Reinikainen T, Claeyssens M, Keranen S, Knowles JK, Teeri TT
Title	Site-directed mutagenesis of the putative catalytic residues of Trichoderma reesei cellobiohydrolase I and endoglucanase I.
Related PDB
Related UniProtKB
[4]
Resource
Comments
Medline ID
PubMed ID	8223652
Journal	Eur J Biochem
Year	1993
Volume	217
Pages	947-53
Authors	Schou C, Rasmussen G, Kaltoft MB, Henrissat B, Schulein M
Title	Stereochemistry, specificity and kinetics of the hydrolysis of reduced cellodextrins by nine cellulases.
Related PDB
Related UniProtKB
[5]
Resource
Comments	X-RAY CRYSTALLOGRAPHY (2.7 ANGSTROMS).
Medline ID	97110317
PubMed ID	8952478
Journal	Biochemistry
Year	1996
Volume	35
Pages	15280-7
Authors	Sulzenbacher G, Driguez H, Henrissat B, Schulein M, Davies GJ
Title	Structure of the Fusarium oxysporum endoglucanase I with a nonhydrolyzable substrate analogue: substrate distortion gives rise to the preferred axial orientation for the leaving group.
Related PDB	1ovw
Related UniProtKB	P46237
[6]
Resource
Comments
Medline ID
PubMed ID	8706890
Journal	FEBS Lett
Year	1996
Volume	390
Pages	339-44
Authors	Henriksson H, Stahlberg J, Isaksson R, Pettersson G
Title	The active sites of cellulases are involved in chiral recognition: a comparison of cellobiohydrolase 1 and endoglucanase 1.
Related PDB
Related UniProtKB
[7]
Resource
Comments
Medline ID
PubMed ID	9153431
Journal	Biochemistry
Year	1997
Volume	36
Pages	5893-901
Authors	Mackenzie LF, Davies GJ, Schulein M, Withers SG
Title	Identification of the catalytic nucleophile of endoglucanase I from Fusarium oxysporum by mass spectrometry.
Related PDB
Related UniProtKB
[8]
Resource
Comments	X-RAY CRYSTALLOGRAPHY (2.3 ANGSTROMS).
Medline ID	97297800
PubMed ID	9153432
Journal	Biochemistry
Year	1997
Volume	36
Pages	5902-11
Authors	Sulzenbacher G, Schulein M, Davies GJ
Title	Structure of the endoglucanase I from Fusarium oxysporum: native, cellobiose, and 3,4-epoxybutyl beta-D-cellobioside-inhibited forms, at 2.3 A resolution.
Related PDB	2ovw 3ovw 4ovw
Related UniProtKB	P46237
[9]
Resource
Comments
Medline ID
PubMed ID	9006908
Journal	J Biol Chem
Year	1997
Volume	272
Pages	2709-13
Authors	Armand S, Drouillard S, Schulein M, Henrissat B, Driguez H
Title	A bifunctionalized fluorogenic tetrasaccharide as a substrate to study cellulases.
Related PDB
Related UniProtKB
[10]
Resource
Comments	X-RAY CRYSTALLOGRAPHY (2.2 ANGSTROMS) OF MUTANT S37W/P39W.
Medline ID	97475713
PubMed ID	9335168
Journal	J Biotechnol
Year	1997
Volume	57
Pages	91-100
Authors	Davies GJ, Ducros V, Lewis RJ, Borchert TV, Schulein M
Title	Oligosaccharide specificity of a family 7 endoglucanase: insertion of potential sugar-binding subsites.
Related PDB	1a39
Related UniProtKB	P56680
[11]
Resource
Comments
Medline ID
PubMed ID	9325098
Journal	J Mol Biol
Year	1997
Volume	272
Pages	383-97
Authors	Kleywegt GJ, Zou JY, Divne C, Davies GJ, Sinning I, Stahlberg J, Reinikainen T, Srisodsuk M, Teeri TT, Jones TA
Title	The crystal structure of the catalytic core domain of endoglucanase I from Trichoderma reesei at 3.6 A resolution, and a comparison with related enzymes.
Related PDB
Related UniProtKB
[12]
Resource
Comments	X-RAY CRYSTALLOGRAPHY (2.2 ANGSTROMS), AND MUTAGENESIS.
Medline ID	98437137
PubMed ID	9761741
Journal	Biochem J
Year	1998
Volume	335
Pages	409-16
Authors	MacKenzie LF, Sulzenbacher G, Divne C, Jones TA, Woldike HF, Schulein M, Withers SG, Davies GJ
Title	Crystal structure of the family 7 endoglucanase I (Cel7B) from Humicola insolens at 2.2 A resolution and identification of the catalytic nucleophile by trapping of the covalent glycosyl-enzyme intermediate.
Related PDB	1dym 2a39
Related UniProtKB	P56680
[13]
Resource
Comments
Medline ID
PubMed ID	11336632
Journal	Biochem J
Year	2001
Volume	356
Pages	19-30
Authors	Becker D, Braet C, Brumer H 3rd, Claeyssens M, Divne C, Fagerstrom BR, Harris M, Jones TA, Kleywegt GJ, Koivula A, Mahdi S, Piens K, Sinnott ML, Stahlberg J, Teeri TT, Underwood M, Wohlfahrt G
Title	Engineering of a glycosidase Family 7 cellobiohydrolase to more alkaline pH optimum: the pH behaviour of Trichoderma reesei Cel7A and its E223S/ A224H/L225V/T226A/D262G mutant.
Related PDB
Related UniProtKB
[14]
Resource
Comments
Medline ID
PubMed ID	11743726
Journal	J Mol Biol
Year	2001
Volume	314
Pages	1097-111
Authors	Munoz IG, Ubhayasekera W, Henriksson H, Szabo I, Pettersson G, Johansson G, Mowbray SL, Stahlberg J
Title	Family 7 cellobiohydrolases from Phanerochaete chrysosporium: crystal structure of the catalytic module of Cel7D (CBH58) at 1.32 A resolution and homology models of the isozymes.
Related PDB
Related UniProtKB
[15]
Resource
Comments	X-ray crystallography
Medline ID
PubMed ID	12890535
Journal	Chem Biol
Year	2003
Volume	10
Pages	619-28
Authors	Ducros VM, Tarling CA, Zechel DL, Brzozowski AM, Frandsen TP, von Ossowski I, Schulein M, Withers SG, Davies GJ
Title	Anatomy of glycosynthesis: structure and kinetics of the Humicola insolens Cel7B E197A and E197S glycosynthase mutants.
Related PDB	1oji 1ojj 1ojk
Related UniProtKB

Comments
This enzyme belongs to the glycosidase family-7. According to the literature [7], [8], [11], [12] & [14], the catalytic reaction proceeds as follows: (0) Asp199 modulates the pKa of Glu197, which is a nucleophile. His213 modulates these residues, Asp199 and Glu197. (1) Glu202 acts as a general acid, to protonate the leaving group, through a water molecule, to give an oxacarbenium ion-like transition state. (SN1-like reaction) (2) Glu197 makes a nucleophilic attack on the C2 atom of the transition-state, to form a glycosyl-enzyme intermediate. (3) Glu202 acts as a general base, to activate the water. (4) The activated water makes a nucleophilic attack on the intermediate, through an oxacarbenium ion-like transition-state, to complete the hydrolysis.

Comments

This enzyme belongs to the glycosidase family-7.
According to the literature [7], [8], [11], [12] & [14], the catalytic reaction proceeds as follows:
(0) Asp199 modulates the pKa of Glu197, which is a nucleophile. His213 modulates these residues, Asp199 and Glu197.
(1) Glu202 acts as a general acid, to protonate the leaving group, through a water molecule, to give an oxacarbenium ion-like transition state. (SN1-like reaction)
(2) Glu197 makes a nucleophilic attack on the C2 atom of the transition-state, to form a glycosyl-enzyme intermediate.
(3) Glu202 acts as a general base, to activate the water.
(4) The activated water makes a nucleophilic attack on the intermediate, through an oxacarbenium ion-like transition-state, to complete the hydrolysis.

Created	Updated
2004-03-22	2009-02-26