Crystal structures of Thermotoga maritima Cel5A, apo form and dimer/au

Experimental Data Snapshot

  • Resolution: 1.40 Å
  • R-Value Free: 0.209 
  • R-Value Work: 0.184 

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Diverse substrate recognition mechanism revealed by Thermotoga maritima Cel5A structures in complex with cellotetraose, cellobiose and mannotriose

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

(2011) Biochim Biophys Acta 1814: 1832-1840

  • DOI: https://doi.org/10.1016/j.bbapap.2011.07.020
  • Primary Citation of Related Structures:  
    3AMC, 3AMD, 3AMG, 3AOF, 3AZR, 3AZS, 3AZT

  • PubMed Abstract: 

    The hyperthermophilic endoglucanase Cel5A from Thermotoga maritima can find applications in lignocellulosic biofuel production, because it catalyzes the hydrolysis of glucan- and mannan-based polysaccharides. Here, we report the crystal structures in apo-form and in complex with three ligands, cellotetraose, cellobiose and mannotriose, at 1.29Å to 2.40Å resolution. The open carbohydrate-binding cavity which can accommodate oligosaccharide substrates with extensively branched chains explained the dual specificity of the enzyme. Combining our structural information and the previous kinetic data, it is suggested that this enzyme prefers β-glucosyl and β-mannosyl moieties at the reducing end and uses two conserved catalytic residues, E253 (nucleophile) and E136 (general acid/base), to hydrolyze the glycosidic bonds. Moreover, our results also suggest that the wide spectrum of Tm_Cel5A substrates might be due to the lack of steric hindrance around the C2-hydroxyl group of the glucose or mannose unit from active-site residues.

  • Organizational Affiliation

    Institute of Biotechnology, National Taiwan University, Taipei, Taiwan.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
A, B
317Thermotoga maritima MSB8Mutation(s): 0 
Gene Names: TM_1751
Find proteins for Q9X273 (Thermotoga maritima (strain ATCC 43589 / DSM 3109 / JCM 10099 / NBRC 100826 / MSB8))
Explore Q9X273 
Go to UniProtKB:  Q9X273
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ9X273
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 1.40 Å
  • R-Value Free: 0.209 
  • R-Value Work: 0.184 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 62.919α = 90
b = 78.34β = 97.25
c = 62.983γ = 90
Software Package:
Software NamePurpose
HKL-2000data collection
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2011-08-10
    Type: Initial release
  • Version 1.1: 2013-06-05
    Changes: Database references
  • Version 1.2: 2024-03-13
    Changes: Data collection, Database references