1HGY

CEL6A D221A mutant


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.258 
  • R-Value Work: 0.198 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

The Active Site of Cellobiohydrolase Cel6A from Trichoderma Reesei: The Roles of Aspartic Acids D221 and D175

Koivula, A.Ruohonen, L.Wohlfahrt, G.Reinikainen, T.Teeri, T.T.Piens, K.Claeyssens, M.Weber, M.Vasella, A.Becker, D.Sinnott, M.L.Zou, J.-Y.Kleywegt, G.J.Szardenings, M.Stahlberg, J.Jones, T.A.

(2002) J.Am.Chem.Soc. 124: 10015

  • Primary Citation of Related Structures:  1HGW

  • PubMed Abstract: 
  • Trichoderma reesei cellobiohydrolase Cel6A is an inverting glycosidase. Structural studies have established that the tunnel-shaped active site of Cel6A contains two aspartic acids, D221 and D175, that are close to the glycosidic oxygen of the scissil ...

    Trichoderma reesei cellobiohydrolase Cel6A is an inverting glycosidase. Structural studies have established that the tunnel-shaped active site of Cel6A contains two aspartic acids, D221 and D175, that are close to the glycosidic oxygen of the scissile bond and at hydrogen-bonding distance from each other. Here, site-directed mutagenesis, X-ray crystallography, and enzyme kinetic studies have been used to confirm the role of residue D221 as the catalytic acid. D175 is shown to affect protonation of D221 and to contribute to the electrostatic stabilization of the partial positive charge in the transition state. Structural and modeling studies suggest that the single-displacement mechanism of Cel6A may not directly involve a catalytic base. The value of (D2O)(V) of 1.16 +/- 0.14 for hydrolysis of cellotriose suggests that the large direct effect expected for proton transfer from the nucleophilic water through a water chain (Grotthus mechanism) is offset by an inverse effect arising from reversibly breaking the short, tight hydrogen bond between D221 and D175 before catalysis.


    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, P.O. Box 1500, FIN-02044 VTT, Espoo, Finland.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
CELLOBIOHYDROLASE CEL6A (FORMERLY CALLED CBH 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 4 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
BMA
Query on BMA

Download SDF File 
Download CCD File 
A
BETA-D-MANNOSE
C6 H12 O6
WQZGKKKJIJFFOK-RWOPYEJCSA-N
 Ligand Interaction
GLC
Query on GLC

Download SDF File 
Download CCD File 
A
ALPHA-D-GLUCOSE
C6 H12 O6
WQZGKKKJIJFFOK-DVKNGEFBSA-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: 2.2 Å
  • R-Value Free: 0.258 
  • R-Value Work: 0.198 
  • Space Group: P 1
Unit Cell:
Length (Å)Angle (°)
a = 49.600α = 76.30
b = 67.500β = 75.20
c = 53.800γ = 78.40
Software Package:
Software NamePurpose
MADNESSdata reduction
MADNESSdata scaling
AMoREphasing
CNSrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2002-01-15
    Type: Initial release
  • Version 1.1: 2011-05-08
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2017-07-12
    Type: Refinement description