The crystal structure of the catalytic core domain of endoglucanase I from Trichoderma reesei at 3.6 angstrom resolution, and a comparison with related enzymes

G J  Kleywegt; J Y  Zou; C  Divne; G J  Davies; I  Sinning; J  Stahlberg; T  Reinikainen; M  Srisodsuk; T T  Teeri; T A  Jones

The crystal structure of the catalytic core domain of endoglucanase I from Trichoderma reesei at 3.6 angstrom resolution, and a comparison with related enzymes

G J Kleywegt, J Y Zou, C Divne, G J Davies, I Sinning, J Stahlberg, T Reinikainen, M Srisodsuk, T T Teeri, T A Jones

Chemistry

Research output: Contribution to journal › Article › peer-review

Abstract

Cellulose is the most abundant polymer in the biosphere. Although generally resistant to degradation, it may be hydrolysed by cellulolytic organisms that have evolved a variety of structurally distinct enzymes, cellobiohydrolases and endoglucanases, for this purpose Endoglucanase I(EG I) is the major endoglucanase produced by the cellulolytic fungus Trichoderma reesei, accounting for 5 to 10% of the total amount of cellulases produced by this organism. Together with EG I from Humicola insolens and T. reesei cellobiohydrolase I (CBH I), the enzyme is classified into family 7 of the glycosyl hydrolases, and it catalyses hydrolysis with a net retention of the anomeric configuration.

The structure of the catalytic core domain (residues 1 to 371) of EG I from T. reesei has been determined at 3.6 Angstrom resolution by the molecular replacement method using the structures of T. reesei CBH I and H. insolens EG I as search models. By employing the 2-fold non-crystallographic symmetry (NCS), the structure was refined successfully, despite the Limited resolution. The final model has an X-factor of 0.201 (R-free 0.258).

The structure of EG I reveals an extended, open substrate-binding cleft, rather than a tunnel as found in the homologous cellobiohydrolase CBH I. This confirms the earlier proposal that the tunnel-forming loops in CBH I have been deleted in EG I, which has resulted in an open active site in EG I, enabling it to function as an endoglucanase. Comparison of the structure of EG I with several related enzymes reveals structural similarities, and differences that relate to their biological function in degrading particular substrates. A possible structural explanation of the drastically different pH profiles of T. reesei and H. insolens EG I is proposed. (C) 1997 Academic Press Limited.

Original language	English
Pages (from-to)	383-397
Number of pages	15
Journal	Journal of Molecular Biology
Volume	272
Issue number	3
Publication status	Published - 26 Sept 1997

Keywords

cellulase
cellulose
endoglucanase
protein structure
X-ray crystallography
PROTEIN-STRUCTURE REFINEMENT
ACID-SEQUENCE SIMILARITIES
3-DIMENSIONAL STRUCTURE
CELLOBIOHYDROLASE-I
ACTIVE-SITE
MACROMOLECULAR STRUCTURES
MOLECULAR REPLACEMENT
CELLULOLYTIC ENZYMES
BACTERIAL CELLULASE
X-RAY

Cite this

@article{4faf9c18f442411e8f15335054b11de0,

title = "The crystal structure of the catalytic core domain of endoglucanase I from Trichoderma reesei at 3.6 angstrom resolution, and a comparison with related enzymes",

abstract = "Cellulose is the most abundant polymer in the biosphere. Although generally resistant to degradation, it may be hydrolysed by cellulolytic organisms that have evolved a variety of structurally distinct enzymes, cellobiohydrolases and endoglucanases, for this purpose Endoglucanase I(EG I) is the major endoglucanase produced by the cellulolytic fungus Trichoderma reesei, accounting for 5 to 10% of the total amount of cellulases produced by this organism. Together with EG I from Humicola insolens and T. reesei cellobiohydrolase I (CBH I), the enzyme is classified into family 7 of the glycosyl hydrolases, and it catalyses hydrolysis with a net retention of the anomeric configuration.The structure of the catalytic core domain (residues 1 to 371) of EG I from T. reesei has been determined at 3.6 Angstrom resolution by the molecular replacement method using the structures of T. reesei CBH I and H. insolens EG I as search models. By employing the 2-fold non-crystallographic symmetry (NCS), the structure was refined successfully, despite the Limited resolution. The final model has an X-factor of 0.201 (R-free 0.258).The structure of EG I reveals an extended, open substrate-binding cleft, rather than a tunnel as found in the homologous cellobiohydrolase CBH I. This confirms the earlier proposal that the tunnel-forming loops in CBH I have been deleted in EG I, which has resulted in an open active site in EG I, enabling it to function as an endoglucanase. Comparison of the structure of EG I with several related enzymes reveals structural similarities, and differences that relate to their biological function in degrading particular substrates. A possible structural explanation of the drastically different pH profiles of T. reesei and H. insolens EG I is proposed. (C) 1997 Academic Press Limited.",

keywords = "cellulase, cellulose, endoglucanase, protein structure, X-ray crystallography, PROTEIN-STRUCTURE REFINEMENT, ACID-SEQUENCE SIMILARITIES, 3-DIMENSIONAL STRUCTURE, CELLOBIOHYDROLASE-I, ACTIVE-SITE, MACROMOLECULAR STRUCTURES, MOLECULAR REPLACEMENT, CELLULOLYTIC ENZYMES, BACTERIAL CELLULASE, X-RAY",

author = "Kleywegt, {G J} and Zou, {J Y} and C Divne and Davies, {G J} and I Sinning and J Stahlberg and T Reinikainen and M Srisodsuk and Teeri, {T T} and Jones, {T A}",

year = "1997",

month = sep,

day = "26",

language = "English",

volume = "272",

pages = "383--397",

journal = "Journal of Molecular Biology",

issn = "0022-2836",

publisher = "Academic Press",

number = "3",

}

TY - JOUR

T1 - The crystal structure of the catalytic core domain of endoglucanase I from Trichoderma reesei at 3.6 angstrom resolution, and a comparison with related enzymes

AU - Kleywegt, G J

AU - Zou, J Y

AU - Divne, C

AU - Davies, G J

AU - Sinning, I

AU - Stahlberg, J

AU - Reinikainen, T

AU - Srisodsuk, M

AU - Teeri, T T

AU - Jones, T A

PY - 1997/9/26

Y1 - 1997/9/26

N2 - Cellulose is the most abundant polymer in the biosphere. Although generally resistant to degradation, it may be hydrolysed by cellulolytic organisms that have evolved a variety of structurally distinct enzymes, cellobiohydrolases and endoglucanases, for this purpose Endoglucanase I(EG I) is the major endoglucanase produced by the cellulolytic fungus Trichoderma reesei, accounting for 5 to 10% of the total amount of cellulases produced by this organism. Together with EG I from Humicola insolens and T. reesei cellobiohydrolase I (CBH I), the enzyme is classified into family 7 of the glycosyl hydrolases, and it catalyses hydrolysis with a net retention of the anomeric configuration.The structure of the catalytic core domain (residues 1 to 371) of EG I from T. reesei has been determined at 3.6 Angstrom resolution by the molecular replacement method using the structures of T. reesei CBH I and H. insolens EG I as search models. By employing the 2-fold non-crystallographic symmetry (NCS), the structure was refined successfully, despite the Limited resolution. The final model has an X-factor of 0.201 (R-free 0.258).The structure of EG I reveals an extended, open substrate-binding cleft, rather than a tunnel as found in the homologous cellobiohydrolase CBH I. This confirms the earlier proposal that the tunnel-forming loops in CBH I have been deleted in EG I, which has resulted in an open active site in EG I, enabling it to function as an endoglucanase. Comparison of the structure of EG I with several related enzymes reveals structural similarities, and differences that relate to their biological function in degrading particular substrates. A possible structural explanation of the drastically different pH profiles of T. reesei and H. insolens EG I is proposed. (C) 1997 Academic Press Limited.

AB - Cellulose is the most abundant polymer in the biosphere. Although generally resistant to degradation, it may be hydrolysed by cellulolytic organisms that have evolved a variety of structurally distinct enzymes, cellobiohydrolases and endoglucanases, for this purpose Endoglucanase I(EG I) is the major endoglucanase produced by the cellulolytic fungus Trichoderma reesei, accounting for 5 to 10% of the total amount of cellulases produced by this organism. Together with EG I from Humicola insolens and T. reesei cellobiohydrolase I (CBH I), the enzyme is classified into family 7 of the glycosyl hydrolases, and it catalyses hydrolysis with a net retention of the anomeric configuration.The structure of the catalytic core domain (residues 1 to 371) of EG I from T. reesei has been determined at 3.6 Angstrom resolution by the molecular replacement method using the structures of T. reesei CBH I and H. insolens EG I as search models. By employing the 2-fold non-crystallographic symmetry (NCS), the structure was refined successfully, despite the Limited resolution. The final model has an X-factor of 0.201 (R-free 0.258).The structure of EG I reveals an extended, open substrate-binding cleft, rather than a tunnel as found in the homologous cellobiohydrolase CBH I. This confirms the earlier proposal that the tunnel-forming loops in CBH I have been deleted in EG I, which has resulted in an open active site in EG I, enabling it to function as an endoglucanase. Comparison of the structure of EG I with several related enzymes reveals structural similarities, and differences that relate to their biological function in degrading particular substrates. A possible structural explanation of the drastically different pH profiles of T. reesei and H. insolens EG I is proposed. (C) 1997 Academic Press Limited.

KW - cellulase

KW - cellulose

KW - endoglucanase

KW - protein structure

KW - X-ray crystallography

KW - PROTEIN-STRUCTURE REFINEMENT

KW - ACID-SEQUENCE SIMILARITIES

KW - 3-DIMENSIONAL STRUCTURE

KW - CELLOBIOHYDROLASE-I

KW - ACTIVE-SITE

KW - MACROMOLECULAR STRUCTURES

KW - MOLECULAR REPLACEMENT

KW - CELLULOLYTIC ENZYMES

KW - BACTERIAL CELLULASE

KW - X-RAY

M3 - Article

SN - 0022-2836

VL - 272

SP - 383

EP - 397

JO - Journal of Molecular Biology

JF - Journal of Molecular Biology

IS - 3

ER -