1DYS

Endoglucanase CEL6B from Humicola insolens


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.6 Å
  • R-Value Free: 0.240 
  • R-Value Work: 0.180 

wwPDB Validation 3D Report Full Report


This is version 1.2 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


  • 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 t ...

    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: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
ENDOGLUCANASE
A, B
348Humicola insolensGene Names: cel6B
EC: 3.2.1.4
Find proteins for Q7SIG5 (Humicola insolens)
Go to UniProtKB:  Q7SIG5
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.6 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 = 90.00
b = 104.451β = 90.00
c = 53.788γ = 90.00
Software Package:
Software NamePurpose
SCALEPACKdata scaling
DENZOdata reduction
AMoREphasing
REFMACrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2001-02-08
    Type: Initial release
  • Version 1.1: 2016-12-28
    Type: Database references, Derived calculations, Non-polymer description, Other, Structure summary, Version format compliance
  • Version 1.2: 2017-07-05
    Type: Data collection