4A05

Structure of the catalytic core domain of the cellobiohydrolase, Cel6A, from Chaetomium thermophilum


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.90 Å
  • R-Value Free: 0.197 
  • R-Value Work: 0.167 
  • R-Value Observed: 0.169 

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Literature

Structure of the Catalytic Core Module of the Chaetomium Thermophilum Family Gh6 Cellobiohydrolase Cel6A.

Thompson, A.J.Heu, T.Shaghasi, T.Benyamino, R.Jones, A.Friis, E.P.Wilson, K.S.Davies, G.J.

(2012) Acta Crystallogr D Biol Crystallogr 68: 875

  • DOI: 10.1107/S0907444912016496
  • Primary Citation of Related Structures:  
    4A05

  • PubMed Abstract: 
  • Cellulases, including cellobiohydrolases and endoglucanases, are important enzymes involved in the breakdown of the polysaccharide cellulose. These catalysts have found widescale industrial applications, particularly in the paper and textile industries, ...

    Cellulases, including cellobiohydrolases and endoglucanases, are important enzymes involved in the breakdown of the polysaccharide cellulose. These catalysts have found widescale industrial applications, particularly in the paper and textile industries, and are now finding use in `second-generation' conversion of biomass to biofuels. Despite this considerable biotechnological application, and undoubted future potential, uncertainty remains as to the exact reaction mechanism of the inverting cellulases found in the GH6 family of carbohydrate-active enzymes. In order to gain additional understanding as to how these societally beneficial biocatalysts function, the crystal structure of a GH6 cellobiohydrolase from Chaetomium thermophilum, CtCel6A, has been solved. This structure reveals a distorted α/β-barrel fold comprising a buried tunnel-like active site quite typical of Cel6A enzymes. Analysis of an enzyme-product complex (cellobiose in the -3 and -2 subsites and cellotetraose in subsites +1 to +4) supports the hypothesis that this group of enzymes act via an atypical single-displacement mechanism. Of particular note in this analysis is an active-centre metal ion, Li(+), the position of which matches the position of the positively charged anomeric carbon of the oxocarbenium-ion-like transition state.


    Organizational Affiliation

    Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5DD, England.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
CELLOBIOHYDROLASE FAMILY 6 A364Chaetomium thermophilumMutation(s): 0 
EC: 3.2.1.91 (PDB Primary Data), 3.2.1 (UniProt)
Find proteins for G0SD43 (Chaetomium thermophilum (strain DSM 1495 / CBS 144.50 / IMI 039719))
Explore G0SD43 
Go to UniProtKB:  G0SD43
Protein Feature View
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  • Reference Sequence
Oligosaccharides

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Entity ID: 2
MoleculeChainsChain Length2D Diagram Glycosylation3D Interactions
2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose
B
2 N-Glycosylation Oligosaccharides Interaction
Entity ID: 3
MoleculeChainsChain Length2D Diagram Glycosylation3D Interactions
beta-D-glucopyranose-(1-4)-beta-D-glucopyranose
C
2 N/A Oligosaccharides Interaction
Entity ID: 4
MoleculeChainsChain Length2D Diagram Glycosylation3D Interactions
beta-D-glucopyranose-(1-4)-beta-D-glucopyranose-(1-4)-beta-D-glucopyranose-(1-4)-beta-D-glucopyranose
D
4 N/A Oligosaccharides Interaction
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
LI
Query on LI

Download Ideal Coordinates CCD File 
A
LITHIUM ION
Li
HBBGRARXTFLTSG-UHFFFAOYSA-N
 Ligand Interaction
Biologically Interesting Molecules (External Reference) 2 Unique
Entity ID: 3
IDChainsNameType/Class2D Diagram3D Interactions
PRD_900005
Query on PRD_900005
Cbeta-cellobioseOligosaccharide /  Metabolism

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Entity ID: 4
IDChainsNameType/Class2D Diagram3D Interactions
PRD_900011
Query on PRD_900011
Dbeta-cellotetraoseOligosaccharide /  Metabolism

--

Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.90 Å
  • R-Value Free: 0.197 
  • R-Value Work: 0.167 
  • R-Value Observed: 0.169 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 49.71α = 90
b = 76.06β = 90
c = 107.24γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
MOSFLMdata reduction
SCALAdata scaling
MOLREPphasing

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2012-07-25
    Type: Initial release
  • Version 1.1: 2012-08-01
    Changes: Structure summary
  • Version 1.2: 2012-08-15
    Changes: Database references
  • Version 2.0: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Atomic model, Data collection, Derived calculations, Non-polymer description, Other, Structure summary