1PZ2

Crystal structure of a transient covalent reaction intermediate of a family 51 alpha-L-arabinofuranosidase


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 0.215 
  • R-Value Work: 0.169 

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This is version 2.2 of the entry. See complete history


Literature

Crystal structure and snapshots along the reaction pathway of a family 51 alpha-L-arabinofuranosidase

Hoevel, K.Shallom, D.Niefind, K.Belakhov, V.Shoham, G.Baasov, T.Shoham, Y.Schomburg, D.

(2003) EMBO J 22: 4922-4932

  • DOI: https://doi.org/10.1093/emboj/cdg494
  • Primary Citation of Related Structures:  
    1PZ2, 1PZ3, 1QW8, 1QW9

  • PubMed Abstract: 

    High-resolution crystal structures of alpha-L-arabinofuranosidase from Geobacillus stearothermophilus T-6, a family 51 glycosidase, are described. The enzyme is a hexamer, and each monomer is organized into two domains: a (beta/alpha)8-barrel and a 12-stranded beta sandwich with jelly-roll topology. The structures of the Michaelis complexes with natural and synthetic substrates, and of the transient covalent arabinofuranosyl-enzyme intermediate represent two stable states in the double displacement mechanism, and allow thorough examination of the catalytic mechanism. The arabinofuranose sugar is tightly bound and distorted by an extensive network of hydrogen bonds. The two catalytic residues are 4.7 A apart, and together with other conserved residues contribute to the stabilization of the oxocarbenium ion-like transition state via charge delocalization and specific protein-substrate interactions. The enzyme is an anti-protonator, and a 1.7 A electrophilic migration of the anomeric carbon takes place during the hydrolysis.


  • Organizational Affiliation

    Institute for Biochemistry, University of Cologne, Cologne 50674, Germany.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Alpha-L-arabinofuranosidase
A, B
502Geobacillus stearothermophilusMutation(s): 1 
Gene Names: ABFA
EC: 3.2.1.55
UniProt
Find proteins for Q9XBQ3 (Geobacillus stearothermophilus)
Explore Q9XBQ3 
Go to UniProtKB:  Q9XBQ3
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ9XBQ3
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 0.215 
  • R-Value Work: 0.169 
  • Space Group: H 3
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 179.43α = 90
b = 179.43β = 90
c = 100.231γ = 120
Software Package:
Software NamePurpose
MAR345data collection
SCALEPACKdata scaling
REFMACrefinement

Structure Validation

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Ligand Structure Quality Assessment 


Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2003-10-07
    Type: Initial release
  • Version 1.1: 2008-04-29
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2017-10-11
    Changes: Refinement description
  • Version 2.0: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Advisory, Atomic model, Data collection, Derived calculations, Structure summary
  • Version 2.1: 2021-10-27
    Changes: Database references, Derived calculations, Structure summary
  • Version 2.2: 2024-10-09
    Changes: Data collection, Structure summary