1CEN

CELLULASE (CELC) MUTANT WITH GLU 140 REPLACED BY GLN COMPLEXED WITH CELLOHEXAOSE


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.30 Å
  • R-Value Free: 0.246 
  • R-Value Work: 0.178 
  • R-Value Observed: 0.178 

wwPDB Validation   3D Report Full Report


This is version 2.0 of the entry. See complete history


Literature

The crystal structure of a family 5 endoglucanase mutant in complexed and uncomplexed forms reveals an induced fit activation mechanism.

Dominguez, R.Souchon, H.Lascombe, M.Alzari, P.M.

(1996) J Mol Biol 257: 1042-1051

  • DOI: 10.1006/jmbi.1996.0222
  • Primary Citation of Related Structures:  
    1CEN, 1CEO

  • PubMed Abstract: 
  • The structures of the Glu140-->Gln mutant of the Clostridium thermocellum endoglucanase CelC in unliganded form (CelC(E140Q)) and in complex with cellohexaose (CelC(E140Q)-Gl(C6)) have been refined to crystallographic R-factors of 19.4% at 1.9 A and 17.8% at 2 ...

    The structures of the Glu140-->Gln mutant of the Clostridium thermocellum endoglucanase CelC in unliganded form (CelC(E140Q)) and in complex with cellohexaose (CelC(E140Q)-Gl(C6)) have been refined to crystallographic R-factors of 19.4% at 1.9 A and 17.8% at 2.3 A resolution, respectively. The structure of CelC(E140Q)-Gl(C6) complex shows two D-glucosyl residues bound to the non-reducing end of the substrate-binding cleft. Comparison of the unliganded and complexes structures reveals conformational changes due to substrate binding, including a significant reorientation of the loop 138-141 which carries the general acid/base catalyst Glu140 in wild-type CelC. Endoglucanase CelC, a family 5 glycohydrolase, exhibits a (beta/alpha)8-fold with an additional subdomain of 54 amino acids inserted between beta-strand 6 and alpha-helix 6. Seven amino acid residues (Arg46, His90, Asn139, Glu140, His198, Tyr200, and Glu280) located close to the catalytic reaction center are strictly conserved in family 5 cellulases. Only three of these residues (His90, Gln140 and Glu280) make direct contacts with the substrate, but all participate in a network of hydrogen bonds which contribute to the stability of the active site architecture and may influence the protonation state of the two catalytic residues. Residue Trp313, which interacts with the nucleophile Glu280 and is within hydrogen bonding distance of the substrate, is involved in a non-proline cis-peptide bond. An aromatic residue occurs at an equivalent position in many other (beta/alpha)8-barrel glycosidases; the presence of a cis-peptide bond at this position in the structures of family 1 beta-glucosidases, family 2 beta-galactosidases, family 5 cellulases, family 17 beta-glucanases, and family 18 chitinases provides further evidence of an evolutionary relationship between glycosyl hydrolases with a (beta/alpha)8- architecture.


    Related Citations: 
    • A Common Protein Fold and Similar Active Site in Two Distinct Families of Beta-Glycanases
      Dominguez, R., Souchon, H., Spinelli, S., Dauter, Z., Wilson, K.S., Chauvaux, S., Beguin, P., Alzari, P.M.
      (1995) Nat Struct Biol 2: 569
    • Site-Directed Mutagenesis of Conserved Residues of Clostridium Thermocellum Endoglucanase Celc
      Navas, J., Beguin, P.
      (1992) Biochem Biophys Res Commun 189: 807

    Organizational Affiliation

    Unité d'Immunologie Structurale, Institut Pasteur, Paris, France.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
CELLULASE CELCA343Acetivibrio thermocellusMutation(s): 1 
Gene Names: celC
EC: 3.2.1.4
UniProt
Find proteins for P0C2S3 (Hungateiclostridium thermocellum)
Explore P0C2S3 
Go to UniProtKB:  P0C2S3
Protein Feature View
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  • Reference Sequence
Oligosaccharides

Help

Entity ID: 2
MoleculeChainsChain Length2D DiagramGlycosylation3D Interactions
beta-D-glucopyranose-(1-4)-beta-D-glucopyranoseB2N/A Oligosaccharides Interaction
Glycosylation Resources
GlyTouCan:  G84824ZO
GlyCosmos:  G84824ZO
Biologically Interesting Molecules (External Reference) 1 Unique
Entity ID: 2
IDChainsNameType/Class2D Diagram3D Interactions
PRD_900005
Query on PRD_900005
Bbeta-cellobioseOligosaccharide / Metabolism Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.30 Å
  • R-Value Free: 0.246 
  • R-Value Work: 0.178 
  • R-Value Observed: 0.178 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 51.4α = 90
b = 84.33β = 90
c = 87.5γ = 90
Software Package:
Software NamePurpose
ARP/wARPmodel building
X-PLORmodel building
X-PLORrefinement
DENZOdata reduction
X-PLORphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 1996-04-03
    Type: Initial release
  • Version 1.1: 2008-03-24
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 2.0: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Atomic model, Data collection, Database references, Derived calculations, Structure summary