Crystal Structure Analysis of a GH30 Endoxylanase from Clostridium papyrosolvens C71

Experimental Data Snapshot

  • Resolution: 2.01 Å
  • R-Value Free: 0.200 
  • R-Value Work: 0.164 
  • R-Value Observed: 0.166 

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A novel member of glycoside hydrolase family 30 subfamily 8 with altered substrate specificity.

St John, F.J.Dietrich, D.Crooks, C.Pozharski, E.Gonzalez, J.M.Bales, E.Smith, K.Hurlbert, J.C.

(2014) Acta Crystallogr D Biol Crystallogr 70: 2950-2958

  • DOI: https://doi.org/10.1107/S1399004714019531
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    Endoxylanases classified into glycoside hydrolase family 30 subfamily 8 (GH30-8) are known to hydrolyze the hemicellulosic polysaccharide glucuronoxylan (GX) but not arabinoxylan or neutral xylooligosaccharides. This is owing to the specificity of these enzymes for the α-1,2-linked glucuronate (GA) appendage of GX. Limit hydrolysis of this substrate produces a series of aldouronates each containing a single GA substituted on the xylose penultimate to the reducing terminus. In this work, the structural and biochemical characterization of xylanase 30A from Clostridium papyrosolvens (CpXyn30A) is presented. This xylanase possesses a high degree of amino-acid identity to the canonical GH30-8 enzymes, but lacks the hallmark β8-α8 loop region which in part defines the function of this GH30 subfamily and its role in GA recognition. CpXyn30A is shown to have a similarly low activity on all xylan substrates, while hydrolysis of xylohexaose revealed a competing transglycosylation reaction. These findings are directly compared with the model GH30-8 enzyme from Bacillus subtilis, XynC. Despite its high sequence identity to the GH30-8 enzymes, CpXyn30A does not have any apparent specificity for the GA appendage. These findings confirm that the typically conserved β8-α8 loop region of these enzymes influences xylan substrate specificity but not necessarily β-1,4-xylanase function.

  • Organizational Affiliation

    Forest Products Laboratory, USDA Forest Service, Madison, Wisconsin, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Glucuronoarabinoxylan endo-1,4-beta-xylanase396Ruminiclostridium papyrosolvens DSM 2782Mutation(s): 0 
Gene Names: Cpap_2855
Find proteins for F1TBY8 (Ruminiclostridium papyrosolvens DSM 2782)
Explore F1TBY8 
Go to UniProtKB:  F1TBY8
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupF1TBY8
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.01 Å
  • R-Value Free: 0.200 
  • R-Value Work: 0.164 
  • R-Value Observed: 0.166 
  • Space Group: C 2 2 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 66.02α = 90
b = 76.52β = 90
c = 150.55γ = 90
Software Package:
Software NamePurpose
SCALAdata scaling
PDB_EXTRACTdata extraction
HKL-2000data collection
MOSFLMdata reduction

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2013-06-19
    Type: Initial release
  • Version 1.1: 2014-11-12
    Changes: Database references
  • Version 1.2: 2015-01-07
    Changes: Database references
  • Version 1.3: 2024-02-28
    Changes: Data collection, Database references