1DYS

Endoglucanase CEL6B from Humicola insolens


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.60 Å
  • R-Value Free: 0.240 
  • R-Value Work: 0.180 

Starting Model: other
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This is version 1.4 of the entry. See complete history


Literature

Structure and Function of Humicola Insolens Family 6 Cellulases: Structure of the Endoglucanase, Cel6B, at 1.6 A Resolution

Davies, G.J.Brzozowski, A.M.Dauter, M.Varrot, A.Schulein, M.

(2000) Biochem J 348: 201

  • Primary Citation of Related Structures:  
    1DYS

  • PubMed Abstract: 

    Cellulases are traditionally classified as either endoglucanases or cellobiohydrolases on the basis of their respective catalytic activities on crystalline cellulose, which is generally hydrolysed more efficiently only by the cellobiohydrolases. On the basis of the Trichoderma reesei cellobiohydrolase II structure, it was proposed that the active-site tunnel of cellobiohydrolases permitted the processive hydrolysis of cellulose, whereas the corresponding endoglucanases would display open active-site clefts [Rouvinen, Bergfors, Teeri, Knowles and Jones (1990) Science 249, 380-386]. Glycoside hydrolase family 6 contains both cellobiohydrolases and endoglucanases. The structure of the catalytic core of the family 6 endoglucanase Cel6B from Humicola insolens has been solved by molecular replacement with the known T. reesei cellobiohydrolase II as the search model. Strangely, at the sequence level, this enzyme exhibits the highest sequence similarity to family 6 cellobiohydrolases and displays just one of the loop deletions traditionally associated with endoglucanases in this family. However, this enzyme shows no activity on crystalline substrates but a high activity on soluble substrates, which is typical of an endoglucanase. The three-dimensional structure reveals that the deletion of just a single loop of the active site, coupled with the resultant conformational change in a second 'cellobiohydrolase-specific' loop, peels open the active-site tunnel to reveal a substrate-binding groove.


  • Organizational Affiliation

    Department of Chemistry, University of York, Heslington, York YO10 5DD, U.K. davies@yorvic.york.ac.uk


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
ENDOGLUCANASE
A, B
348Mycothermus thermophilusMutation(s): 0 
EC: 3.2.1.4
UniProt
Find proteins for Q7SIG5 (Humicola insolens)
Explore Q7SIG5 
Go to UniProtKB:  Q7SIG5
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ7SIG5
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.60 Å
  • R-Value Free: 0.240 
  • R-Value Work: 0.180 
  • Space Group: P 21 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 109.917α = 90
b = 104.451β = 90
c = 53.788γ = 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: 2001-02-08
    Type: Initial release
  • Version 1.1: 2016-12-28
    Changes: Database references, Derived calculations, Non-polymer description, Other, Structure summary, Version format compliance
  • Version 1.2: 2017-07-05
    Changes: Data collection
  • Version 1.3: 2024-05-01
    Changes: Data collection, Database references, Other, Refinement description
  • Version 1.4: 2024-11-13
    Changes: Structure summary