Crystal structure of Pseudomonas aeruginosa flagellin FliC

Experimental Data Snapshot

  • Resolution: 2.10 Å
  • R-Value Free: 0.205 
  • R-Value Work: 0.161 
  • R-Value Observed: 0.164 

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Crystal structure of FliC flagellin from Pseudomonas aeruginosa and its implication in TLR5 binding and formation of the flagellar filament

Song, W.S.Yoon, S.I.

(2014) Biochem Biophys Res Commun 444: 109-115

  • DOI: https://doi.org/10.1016/j.bbrc.2014.01.008
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    Pseudomonas aeruginosa is one of leading opportunistic pathogens in humans and its movement is driven by a flagellar filament that is constituted through the polymerization of a single protein, FliC flagellin (paFliC). paFliC is an essential virulence factor for the colonization of P. aeruginosa. paFliC activates innate immune responses via its recognition by Toll-like receptor 5 (TLR5) and adaptive immunity in the host. Thus, paFliC has been a vaccine candidate to prevent P. aeruginosa infection, particularly for cystic fibrosis patients. To provide structural information on paFliC and its flagellar filament, we have determined the crystal structure of paFliC, which contains the conserved D1 and variable D2 domains, at 2.1 Å resolution. As observed for Salmonella FliC, the paFliC D1 domain is folded into a rod-shaped structure, and paFliC was demonstrated by gel filtration and native PAGE analyses to directly interact with TLR5. Moreover, a structural model of the paFliC-TLR5 complex suggests that paFliC D1 would provide major TLR5-binding sites, similar to Salmonella FliC. In contrast to the D1 domain, the paFliC D2 domain exhibits a unique structure of two β-sheets and one α-helix that has not been found in other flagellins. An in silico construction of a flagellar filament based on the packing of paFliC in the crystal suggests that the D2 domain would be exposed to solution and could play an important role in immunogenicity. Our biophysical and structure-based modeling study on paFliC, the paFliC-TLR5 complex, and the paFliC filament could contribute to the improvement of vaccine design to control P. aeruginosa infection.

  • Organizational Affiliation

    Department of Systems Immunology and Institute of Antibody Research, College of Biomedical Science, Kangwon National University, Chuncheon 200-701, Republic of Korea. Electronic address: sungil@kangwon.ac.kr.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Flagellin293Pseudomonas aeruginosaMutation(s): 1 
Gene Names: fliC
Find proteins for O86266 (Pseudomonas aeruginosa)
Explore O86266 
Go to UniProtKB:  O86266
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupO86266
Sequence Annotations
  • Reference Sequence
Small Molecules
Modified Residues  1 Unique
IDChains TypeFormula2D DiagramParent
Query on MSE
Experimental Data & Validation

Experimental Data

  • Resolution: 2.10 Å
  • R-Value Free: 0.205 
  • R-Value Work: 0.161 
  • R-Value Observed: 0.164 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 45.347α = 90
b = 60.267β = 111.18
c = 46.611γ = 90
Software Package:
Software NamePurpose
HKL-2000data collection
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2014-01-29
    Type: Initial release
  • Version 1.1: 2014-03-05
    Changes: Database references