3AMQ

E134C-Cellobiose co-crystal of cellulase 12A from thermotoga maritima


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.80 Å
  • R-Value Free: 0.230 
  • R-Value Work: 0.190 
  • R-Value Observed: 0.195 

Starting Model: experimental
View more details

wwPDB Validation   3D Report Full Report


Ligand Structure Quality Assessment 


This is version 2.1 of the entry. See complete history


Literature

Crystal structure and substrate-binding mode of cellulase 12A from Thermotoga maritima

Cheng, Y.-S.Ko, T.-P.Wu, T.-H.Ma, Y.Huang, C.-H.Lai, H.-L.Wang, A.H.-J.Liu, J.-R.Guo, R.-T.

(2011) Proteins 79: 1193-1204

  • DOI: https://doi.org/10.1002/prot.22953
  • Primary Citation of Related Structures:  
    3AMH, 3AMM, 3AMN, 3AMP, 3AMQ

  • PubMed Abstract: 

    Cellulases have been used in many applications to treat various carbohydrate-containing materials. Thermotoga maritima cellulase 12A (TmCel12A) belongs to the GH12 family of glycoside hydrolases. It is a β-1,4-endoglucanase that degrades cellulose molecules into smaller fragments, facilitating further utilization of the carbohydrate. Because of its hyperthermophilic nature, the enzyme is especially suitable for industrial applications. Here the crystal structure of TmCel12A was determined by using an active-site mutant E134C and its mercury-containing derivatives. It adopts a β-jellyroll protein fold typical of the GH12-family enzymes, with two curved β-sheets A and B and a central active-site cleft. Structural comparison with other GH12 enzymes shows significant differences, as found in two longer and highly twisted β-strands B8 and B9 and several loops. A unique Loop A3-B3 that contains Arg60 and Tyr61 stabilizes the substrate by hydrogen bonding and stacking, as observed in the complex crystals with cellotetraose and cellobiose. The high-resolution structures allow clear elucidation of the network of interactions between the enzyme and its substrate. The sugar residues bound to the enzyme appear to be more ordered in the -2 and -1 subsites than in the +1, +2 and -3 subsites. In the E134C crystals the bound -1 sugar at the cleavage site consistently show the α-anomeric configuration, implicating an intermediate-like structure.


  • Organizational Affiliation

    Institute of Biotechnology, National Taiwan University, Taiwan.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Endo-1,4-beta-glucanase
A, B, C, D
265Thermotoga maritimaMutation(s): 1 
EC: 3.2.1.4
UniProt
Find proteins for Q60032 (Thermotoga maritima)
Explore Q60032 
Go to UniProtKB:  Q60032
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ60032
Sequence Annotations
Expand
  • Reference Sequence
Oligosaccharides

Help

Entity ID: 2
MoleculeChains Length2D Diagram Glycosylation3D Interactions
beta-D-glucopyranose-(1-4)-alpha-D-glucopyranose
E, F, G, H
2N/A
Glycosylation Resources
GlyTouCan:  G86802XL
GlyCosmos:  G86802XL
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.80 Å
  • R-Value Free: 0.230 
  • R-Value Work: 0.190 
  • R-Value Observed: 0.195 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 230.896α = 90
b = 46.907β = 114.19
c = 116.409γ = 90
Software Package:
Software NamePurpose
Blu-Icedata collection
CNSrefinement
HKL-2000data reduction
HKL-2000data scaling
CNSphasing

Structure Validation

View Full Validation Report



Ligand Structure Quality Assessment 


Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2011-03-16
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2014-01-29
    Changes: Database references
  • Version 1.3: 2017-10-11
    Changes: Refinement description
  • Version 2.0: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Atomic model, Data collection, Database references, Derived calculations, Non-polymer description, Structure summary
  • Version 2.1: 2023-11-01
    Changes: Data collection, Database references, Refinement description, Structure summary