1DYM

Humicola insolens Endocellulase Cel7B (EG 1) E197A Mutant


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.75 Å
  • R-Value Free: 0.200 
  • R-Value Work: 0.158 

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This is version 2.1 of the entry. See complete history


Literature

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.

MacKenzie, L.F.Sulzenbacher, G.Divne, C.Jones, T.A.Woldike, H.F.Schulein, M.Withers, S.G.Davies, G.J.

(1998) Biochem J 335 ( Pt 2): 409-416

  • DOI: 10.1042/bj3350409
  • Primary Citation of Related Structures:  
    2A39, 1DYM

  • PubMed Abstract: 
  • Cellulose is the major polysaccharide component of the plant cell wall and the most abundant naturally produced macromolecule on Earth. The enzymic degradation of cellulose, by cellulases, is therefore of great environmental and commercial significance. Cellulases are found in 12 of the glycoside hydrolase families classified according to their amino acid sequence similarities ...

    Cellulose is the major polysaccharide component of the plant cell wall and the most abundant naturally produced macromolecule on Earth. The enzymic degradation of cellulose, by cellulases, is therefore of great environmental and commercial significance. Cellulases are found in 12 of the glycoside hydrolase families classified according to their amino acid sequence similarities. Endoglucanase I (Cel7B), from the soft-rot fungus Humicola insolens, is a family 7 enzyme. The structure of the native form of Cel7B from H. insolens at 2.2 A resolution has been solved by molecular replacement using the known Trichoderma reesei cellobiohydrolase I [Divne, Ståhlberg, Reinikainen, Ruohonen, Pettersson, Knowles, Teeri and Jones (1994) Science 265, 524-528] structure as the search model. Cel7B catalyses hydrolysis of the beta-1,4 glycosidic linkages in cellulose with net retention of anomeric configuration. The catalytic nucleophile at the active site of Cel7B has been identified as Glu-197 by trapping of a 2-deoxy-2-fluorocellotriosyl enzyme intermediate and identification of the labelled peptide in peptic digests by tandem MS. Site-directed mutagenesis of both Glu-197 and the prospective catalytic acid, Glu-202, results in inactive enzyme, confirming the critical role of these groups for catalysis.


    Related Citations: 
    • Oligosaccharide Specificity of a Family 7 Endoglucanase: Insertion of Potential Sugar-Binding Subsites
      Davies, G.J., Ducros, V., Lewis, R.J., Borchert, T.V., Schulein, M.
      (1997) J Biotechnol 57: 91

    Organizational Affiliation

    Department of Chemistry, University of British Columbia, Vancouver, V6T 1Z1, Canada.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
ENDOGLUCANASE IA402Humicola insolensMutation(s): 1 
Gene Names: CEL7B
EC: 3.2.1.4
UniProt
Find proteins for P56680 (Humicola insolens)
Explore P56680 
Go to UniProtKB:  P56680
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
NAG
Query on NAG

Download Ideal Coordinates CCD File 
B [auth A], C [auth A]2-acetamido-2-deoxy-beta-D-glucopyranose
C8 H15 N O6
OVRNDRQMDRJTHS-FMDGEEDCSA-N
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
PCA
Query on PCA
AL-PEPTIDE LINKINGC5 H7 N O3GLN
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.75 Å
  • R-Value Free: 0.200 
  • R-Value Work: 0.158 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 49.969α = 90
b = 74.284β = 103.82
c = 60.146γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
DENZOdata reduction
SCALEPACKdata scaling
AMoREphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2000-02-04
    Type: Initial release
  • Version 1.1: 2014-01-29
    Changes: Database references, Derived calculations, Non-polymer description, Other, Structure summary, Version format compliance
  • Version 1.2: 2019-07-24
    Changes: Data collection, Derived calculations
  • Version 1.3: 2019-10-09
    Changes: Data collection, Database references, Other
  • Version 2.0: 2020-03-11
    Changes: Data collection, Polymer sequence
  • Version 2.1: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Data collection, Derived calculations, Structure summary