2CEL

ACTIVE-SITE MUTANT E212Q DETERMINED AT PH 6.0 WITH NO LIGAND BOUND IN THE ACTIVE SITE


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 0.208 
  • R-Value Work: 0.184 
  • R-Value Observed: 0.184 

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Ligand Structure Quality Assessment 


This is version 2.1 of the entry. See complete history


Literature

Activity studies and crystal structures of catalytically deficient mutants of cellobiohydrolase I from Trichoderma reesei.

Stahlberg, J.Divne, C.Koivula, A.Piens, K.Claeyssens, M.Teeri, T.T.Jones, T.A.

(1996) J Mol Biol 264: 337-349

  • DOI: 10.1006/jmbi.1996.0644
  • Primary Citation of Related Structures:  
    4CEL, 3CEL, 2CEL

  • PubMed Abstract: 
  • The roles of the residues in the catalytic trio Glu212-Asp214-Glu217 in cellobiohydrolase I (CBHI) from Trichoderma reesei have been investigated by changing these residues to their isosteric amide counterparts. Three mutants, E212Q, D214N and E217Q, were constructed and expressed in T ...

    The roles of the residues in the catalytic trio Glu212-Asp214-Glu217 in cellobiohydrolase I (CBHI) from Trichoderma reesei have been investigated by changing these residues to their isosteric amide counterparts. Three mutants, E212Q, D214N and E217Q, were constructed and expressed in T. reesei. All three point mutations significantly impair the catalytic activity of the enzyme, although all retain some residual activity. On the small chromophoric substrate CNP-Lac, the kcat values were reduced to 1/2000, 1/85 and 1/370 of the wild-type activity, respectively, whereas the KM values remained essentially unchanged. On insoluble crystalline cellulose, BMCC, no significant activity was detected for the E212Q and E217Q mutants, whereas the D214N mutant retained residual activity. The consequences of the individual mutations on the active-site structure were assessed for two of the mutants, E212Q and D214N, by X-ray crystallography at 2.0 A and 2.2 A resolution, respectively. In addition, the structure of E212Q CBHI in complex with the natural product, cellobiose, was determined at 2.0 A resolution. The active-site structure of each mutant is very similar to that of the wild-type enzyme. In the absence of ligand, the active site of the D214N mutant contains a calcium ion firmly bound to Glu212, whereas that of E212Q does not. This supports our hypothesis that Glu212 is the charged species during catalysis. As in the complex of wild-type CBHI with bound o-iodobenzyl-1-thio-beta-D-glucoside, cellobiose is bound to the two product sites in the complex with E212Q. However, the binding of cellobiose differs from that of the glucoside in that the cellobiose is shifted away from the trio of catalytic residues to interact more intimately with a loop that is part of the outer wall of the active site.


    Related Citations: 
    • The Three-Dimensional Crystal Structure of the Catalytic Core of Cellobiohydrolase I from Trichoderma Reesei
      Divne, C., Stahlberg, J., Reinikainen, T., Ruohonen, L., Pettersson, G., Knowles, J.K., Teeri, T.T., Jones, T.A.
      (1994) Science 265: 524
    • Crystallization and Preliminary X-Ray Studies on the Core Proteins of Cellobiohydrolase I and Endoglucanase I from Trichoderma Reesei
      Divne, C., Sinning, I., Stahlberg, J., Pettersson, G., Bailey, M., Siika-Aho, M., Margolles-Clark, E., Teeri, T., Jones, T.A.
      (1993) J Mol Biol 234: 905

    Organizational Affiliation

    Department of Molecular Biology, University of Uppsala, Sweden.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
1,4-BETA-D-GLUCAN CELLOBIOHYDROLASE IA, B434Trichoderma reeseiMutation(s): 1 
Gene Names: cbh1
EC: 3.2.1.91
UniProt
Find proteins for P62694 (Hypocrea jecorina)
Explore P62694 
Go to UniProtKB:  P62694
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
NAG (Subject of Investigation/LOI)
Query on NAG

Download Ideal Coordinates CCD File 
C [auth A], E [auth B]2-acetamido-2-deoxy-beta-D-glucopyranose
C8 H15 N O6
OVRNDRQMDRJTHS-FMDGEEDCSA-N
 Ligand Interaction
CA
Query on CA

Download Ideal Coordinates CCD File 
D [auth A], F [auth B]CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
PCA
Query on PCA
A, BL-PEPTIDE LINKINGC5 H7 N O3GLN
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 0.208 
  • R-Value Work: 0.184 
  • R-Value Observed: 0.184 
  • Space Group: P 21 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 84α = 90
b = 86.2β = 90
c = 111.5γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
CCP4data reduction
X-PLORmodel building
X-PLORrefinement
CCP4data scaling
X-PLORphasing

Structure Validation

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Ligand Structure Quality Assessment  



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 1997-03-12
    Type: Initial release
  • Version 1.1: 2008-03-24
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Non-polymer description, Version format compliance
  • Version 2.0: 2019-12-25
    Changes: Database references, Derived calculations, Polymer sequence
  • Version 2.1: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Data collection, Derived calculations, Structure summary