Crystal structure of bacterial FucU

Experimental Data Snapshot

  • Resolution: 1.90 Å
  • R-Value Free: 0.245 
  • R-Value Work: 0.198 
  • R-Value Observed: 0.198 

Starting Model: experimental
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Crystal Structures and Enzyme Mechanism of a Dual Fucose Mutarotase/Ribose Pyranase

Lee, K.-H.Ryu, K.-S.Kim, M.-S.Suh, H.-Y.Ku, B.Song, Y.-L.Ko, S.Lee, W.Oh, B.-H.

(2009) J Mol Biol 391: 178

  • DOI: https://doi.org/10.1016/j.jmb.2009.06.022
  • Primary Citation of Related Structures:  
    2WCU, 2WCV

  • PubMed Abstract: 

    Escherichia coli FucU (Fucose Unknown) is a dual fucose mutarotase and ribose pyranase, which shares 44% sequence identity with its human counterpart. Herein, we report the structures of E. coli FucU and mouse FucU bound to L-fucose and delineate the catalytic mechanisms underlying the interconversion between stereoisomers of fucose and ribose. E. coli FucU forms a decameric toroid with each active site formed by two adjacent subunits. While one subunit provides most of the fucose-interacting residues including a catalytic tyrosine residue, the other subunit provides a catalytic His-Asp dyad. This active-site feature is critical not only for the mutarotase activity toward L-fucose but also for the pyranase activity toward D-ribose. Structural and biochemical analyses pointed that mouse FucU assembles into four different oligomeric forms, among which the smallest homodimeric form is most abundant and would be the predominant species under physiological conditions. This homodimer has two fucose-binding sites that are devoid of the His-Asp dyad and catalytically inactive, indicating that the mutarotase and the pyranase activities appear dispensable in vertebrates. The defective assembly of the mouse FucU homodimer into the decameric form is due to an insertion of two residues at the N-terminal extreme, which is a common aspect of all the known vertebrate FucU proteins. Therefore, vertebrate FucU appears to serve for as yet unknown function through the quaternary structural alteration.

  • Organizational Affiliation

    Center for Biomolecular Recognition, Division of Molecular and Life Sciences, Pohang University of Science and Technology, Pohang, Kyungbuk, Korea.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
A, B, C, D, E
A, B, C, D, E, F, G, H, I, J
140Escherichia coliMutation(s): 0 
EC: 5.1.3
Find proteins for P0AEN8 (Escherichia coli (strain K12))
Explore P0AEN8 
Go to UniProtKB:  P0AEN8
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP0AEN8
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 1.90 Å
  • R-Value Free: 0.245 
  • R-Value Work: 0.198 
  • R-Value Observed: 0.198 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 131.976α = 90
b = 84.481β = 92.02
c = 113.076γ = 90
Software Package:
Software NamePurpose
HKL-2000data reduction
SCALEPACKdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2009-11-10
    Type: Initial release
  • Version 1.1: 2011-05-08
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Data collection, Derived calculations, Other, Structure summary
  • Version 1.4: 2023-12-13
    Changes: Data collection, Database references, Refinement description, Structure summary