4QB6

Structure of CBM35 in complex with aldouronic acid


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.35 Å
  • R-Value Free: 0.177 
  • R-Value Work: 0.164 
  • R-Value Observed: 0.165 

Starting Model: experimental
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wwPDB Validation   3D Report Full Report


This is version 2.1 of the entry. See complete history


Literature

Structural Analysis of Glucuronoxylan-specific Xyn30D and Its Attached CBM35 Domain Gives Insights into the Role of Modularity in Specificity.

Sainz-Polo, M.A.Valenzuela, S.V.Gonzalez, B.Pastor, F.I.Sanz-Aparicio, J.

(2014) J Biol Chem 289: 31088-31101

  • DOI: https://doi.org/10.1074/jbc.M114.597732
  • Primary Citation of Related Structures:  
    4QAW, 4QB1, 4QB2, 4QB6

  • PubMed Abstract: 

    Glucuronoxylanase Xyn30D is a modular enzyme containing a family 30 glycoside hydrolase catalytic domain and an attached carbohydrate binding module of the CBM35 family. We present here the three-dimensional structure of the full-length Xyn30D at 2.4 Å resolution. The catalytic domain folds into an (α/β)8 barrel with an associated β-structure, whereas the attached CBM35 displays a jellyroll β-sandwich including two calcium ions. Although both domains fold in an independent manner, the linker region makes polar interactions with the catalytic domain, allowing a moderate flexibility. The ancillary Xyn30D-CBM35 domain has been expressed and crystallized, and its binding abilities have been investigated by soaking experiments. Only glucuronic acid-containing ligands produced complexes, and their structures have been solved. A calcium-dependent glucuronic acid binding site shows distinctive structural features as compared with other uronic acid-specific CBM35s, because the presence of two aromatic residues delineates a wider pocket. The nonconserved Glu(129) makes a bidentate link to calcium and defines region E, previously identified as specificity hot spot. The molecular surface of Xyn30D-CBM35 shows a unique stretch of negative charge distribution extending from its binding pocket that might indicate some oriented interaction with its target substrate. The binding ability of Xyn30D-CBM35 to different xylans was analyzed by affinity gel electrophoresis. Some binding was observed with rye glucuronoarabinoxylan in presence of calcium chelating EDTA, which would indicate that Xyn30D-CBM35 might establish interaction to other components of xylan, such as arabinose decorations of glucuronoarabinoxylan. A role in depolymerization of highly substituted chemically complex xylans is proposed.


  • Organizational Affiliation

    From the Departamento de Cristalografía y Biología Estructural, Instituto de Química-Física Rocasolano, CSIC, 28006 Madrid, Spain and.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Xyn30D164Paenibacillus barcinonensisMutation(s): 0 
Gene Names: xyn30d
EC: 3.2.1.8
UniProt
Find proteins for H6WCZ0 (Paenibacillus barcinonensis)
Explore H6WCZ0 
Go to UniProtKB:  H6WCZ0
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupH6WCZ0
Sequence Annotations
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  • Reference Sequence
Oligosaccharides

Help

Entity ID: 2
MoleculeChains Length2D Diagram Glycosylation3D Interactions
alpha-D-glucopyranuronic acid-(1-2)-beta-D-xylopyranose
B
2N/A
Glycosylation Resources
GlyTouCan:  G15382LF
GlyCosmos:  G15382LF
GlyGen:  G15382LF
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.35 Å
  • R-Value Free: 0.177 
  • R-Value Work: 0.164 
  • R-Value Observed: 0.165 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 39.78α = 90
b = 47.35β = 90
c = 103.03γ = 90
Software Package:
Software NamePurpose
MOLREPphasing
REFMACrefinement
XDSdata reduction
SCALAdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2014-10-08
    Type: Initial release
  • Version 1.1: 2014-11-26
    Changes: Database references
  • Version 1.2: 2017-11-22
    Changes: Refinement description
  • Version 1.3: 2018-01-24
    Changes: Refinement description
  • Version 2.0: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Advisory, Atomic model, Data collection, Database references, Derived calculations, Structure summary
  • Version 2.1: 2023-09-20
    Changes: Data collection, Database references, Refinement description, Structure summary