1CB2

CELLOBIOHYDROLASE II, CATALYTIC DOMAIN, MUTANT Y169F


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.232 
  • R-Value Work: 0.210 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

The active site of Trichoderma reesei cellobiohydrolase II: the role of tyrosine 169.

Koivula, A.Reinikainen, T.Ruohonen, L.Valkeajarvi, A.Claeyssens, M.Teleman, O.Kleywegt, G.J.Szardenings, M.Rouvinen, J.Jones, T.A.Teeri, T.T.

(1996) Protein Eng. 9: 691-699


  • PubMed Abstract: 
  • Trichoderma reesei cellobiohydrolase II (CBHII) is an exoglucanase cleaving primarily cellobiose units from the non-reducing end of cellulose chains. The beta-1,4 glycosidic bond is cleaved by acid catalysis with an aspartic acid, D221, as the likely ...

    Trichoderma reesei cellobiohydrolase II (CBHII) is an exoglucanase cleaving primarily cellobiose units from the non-reducing end of cellulose chains. The beta-1,4 glycosidic bond is cleaved by acid catalysis with an aspartic acid, D221, as the likely proton donor, and another aspartate, D175, probably ensuring its protonation and stabilizing charged reaction intermediates. The catalytic base has not yet been identified experimentally. The refined crystal structure of CBHII also shows a tyrosine residue, Y169, located close enough to the scissile bond to be involved in catalysis. The role of this residue has been studied by introducing a mutation Y169F, and analysing the kinetic and binding behavior of the mutated CBHII. The crystal structure of the mutated enzyme was determined to 2.0 A resolution showing no changes when compared with the structure of native CBHII. However, the association constants of the mutant enzyme for cellobiose and cellotriose are increased threefold and for 4-methylumbelliferyl cellobioside over 50-fold. The catalytic constants towards cellotriose and cellotetraose are four times lower for the mutant. These data suggest that Y169, on interacting with a glucose ring entering the second subsite in a narrow tunnel, helps to distort the glucose ring into a more reactive conformation. In addition, a change in the pH activity profile was observed. This indicates that Y169 may have a second role in the catalysis, namely to affect the protonation state of the active site carboxylates, D175 and D221.


    Related Citations: 
    • Three-Dimensional Structure of Cellobiohydrolase II from Trichoderma Reesei
      Rouvinen, J.,Bergfors, T.,Teeri, T.,Knowles, J.K.,Jones, T.A.
      (1990) Science 249: 380


    Organizational Affiliation

    VTT Biotechnology and Food Research, Espoo, Finland.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
CELLOBIOHYDROLASE II
A, B
365Hypocrea jecorinaGene Names: cbh2
EC: 3.2.1.91
Find proteins for P07987 (Hypocrea jecorina)
Go to UniProtKB:  P07987
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
MAN
Query on MAN

Download SDF File 
Download CCD File 
A, B
ALPHA-D-MANNOSE
C6 H12 O6
WQZGKKKJIJFFOK-PQMKYFCFSA-N
 Ligand Interaction
NAG
Query on NAG

Download SDF File 
Download CCD File 
A, B
N-ACETYL-D-GLUCOSAMINE
C8 H15 N O6
OVRNDRQMDRJTHS-FMDGEEDCSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.232 
  • R-Value Work: 0.210 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 49.100α = 90.00
b = 75.800β = 103.20
c = 92.900γ = 90.00
Software Package:
Software NamePurpose
X-PLORrefinement
HAMLINdata reduction
HAMLINdata collection

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1996-10-14
    Type: Initial release
  • Version 1.1: 2008-03-24
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Non-polymer description, Version format compliance