Crystal structure of TDP-fucosamine acetyltransferase (WecD)- complex with acetyl-CoA

Experimental Data Snapshot

  • Resolution: 1.66 Å
  • R-Value Free: 0.223 
  • R-Value Work: 0.202 
  • R-Value Observed: 0.204 

Starting Model: experimental
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Crystal Structure of TDP-Fucosamine Acetyltransferase (WecD) from Escherichia coli, an Enzyme Required for Enterobacterial Common Antigen Synthesis.

Hung, M.N.Rangarajan, E.Munger, C.Nadeau, G.Sulea, T.Matte, A.

(2006) J Bacteriol 188: 5606-5617

  • DOI: https://doi.org/10.1128/JB.00306-06
  • Primary Citation of Related Structures:  
    2FS5, 2FT0

  • PubMed Abstract: 

    Enterobacterial common antigen (ECA) is a polysaccharide found on the outer membrane of virtually all gram-negative enteric bacteria and consists of three sugars, N-acetyl-d-glucosamine, N-acetyl-d-mannosaminuronic acid, and 4-acetamido-4,6-dideoxy-d-galactose, organized into trisaccharide repeating units having the sequence -->3)-alpha-d-Fuc4NAc-(1-->4)-beta-d-ManNAcA-(1-->4)-alpha-d-GlcNAc-(1-->. While the precise function of ECA is unknown, it has been linked to the resistance of Shiga-toxin-producing Escherichia coli (STEC) O157:H7 to organic acids and the resistance of Salmonella enterica to bile salts. The final step in the synthesis of 4-acetamido-4,6-dideoxy-d-galactose, the acetyl-coenzyme A (CoA)-dependent acetylation of the 4-amino group, is carried out by TDP-fucosamine acetyltransferase (WecD). We have determined the crystal structure of WecD in apo form at a 1.95-Angstrom resolution and bound to acetyl-CoA at a 1.66-Angstrom resolution. WecD is a dimeric enzyme, with each monomer adopting the GNAT N-acetyltransferase fold, common to a number of enzymes involved in acetylation of histones, aminoglycoside antibiotics, serotonin, and sugars. The crystal structure of WecD, however, represents the first structure of a GNAT family member that acts on nucleotide sugars. Based on this cocrystal structure, we have used flexible docking to generate a WecD-bound model of the acetyl-CoA-TDP-fucosamine tetrahedral intermediate, representing the structure during acetyl transfer. Our structural data show that WecD does not possess a residue that directly functions as a catalytic base, although Tyr208 is well positioned to function as a general acid by protonating the thiolate anion of coenzyme A.

  • Organizational Affiliation

    Biotechnology Research Institute, 6100 Royalmount Ave., Montreal QC, Canada H4P 2R2.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
TDP-fucosamine acetyltransferase
A, B
235Escherichia coli CFT073Mutation(s): 0 
Gene Names: wecd
Find proteins for Q8FBQ3 (Escherichia coli O6:H1 (strain CFT073 / ATCC 700928 / UPEC))
Explore Q8FBQ3 
Go to UniProtKB:  Q8FBQ3
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ8FBQ3
Sequence Annotations
  • Reference Sequence
Small Molecules
Experimental Data & Validation

Experimental Data

  • Resolution: 1.66 Å
  • R-Value Free: 0.223 
  • R-Value Work: 0.202 
  • R-Value Observed: 0.204 
  • Space Group: P 43 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 84.9α = 90
b = 84.9β = 90
c = 154.122γ = 90
Software Package:
Software NamePurpose
HKL-2000data reduction
SCALEPACKdata scaling

Structure Validation

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Entry History 

Revision History  (Full details and data files)

  • Version 1.0: 2006-08-01
    Type: Initial release
  • Version 1.1: 2008-05-01
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Source and taxonomy, Version format compliance
  • Version 1.3: 2023-08-30
    Changes: Data collection, Database references, Derived calculations, Refinement description