Crystal structure of FliS from H. pylori

Experimental Data Snapshot

  • Resolution: 2.70 Å
  • R-Value Free: 0.284 
  • R-Value Work: 0.238 
  • R-Value Observed: 0.240 

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Molecular interaction of flagellar export chaperone FliS and cochaperone HP1076 in Helicobacter pylori

Lam, W.W.L.Woo, E.J.Kotaka, M.Tam, W.K.Leung, Y.C.Ling, T.K.W.Au, S.W.N.

(2010) FASEB J 24: 4020-4032

  • DOI: https://doi.org/10.1096/fj.10-155242
  • Primary Citation of Related Structures:  
    3IQC, 3K1H, 3K1I

  • PubMed Abstract: 

    Flagellar export chaperone FliS prevents premature polymerization of flagellins and is critical for flagellar assembly and bacterial colonization. Previously, a yeast 2-hybrid study identified various FliS-associated proteins in Helicobacter pylori, but the implications of these interactions are not known. Here we demonstrate the biophysical interaction of FliS (HP0753) and the uncharacterized protein HP1076 from H. pylori. HP1076 possesses a cochaperone activity that promotes the folding and chaperone activity of FliS. We further determined the crystal structures of FliS, HP1076, and the binary complex at 2.7, 1.8, and 2.7 Å resolution, respectively. HP1076 adopts a helix-rich bundle structure and interestingly shares a similar fold with a flagellin homologue, hook-associated protein, and FliS. The FliS-HP1076 complex revealed an extensive electrostatic and hydrophobic binding interface, which is distinct from the flagellin binding pocket in FliS. The helical stacking interaction between HP1076 and FliS suggests that HP1076 stabilizes 2 α helices of FliS and therefore the overall structure of the bundle. Our findings provide new insights into flagellar export chaperones and may have implications for other secretion chaperones in the type III secretion system.

  • Organizational Affiliation

    Centre of Protein Science and Crystallography, Department of Biochemistry, Faculty of Science, The Chinese University of Hong Kong, Hong Kong, China.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Flagellar protein
A, B
131Helicobacter pylori 26695Mutation(s): 0 
Gene Names: HP_0753
Find proteins for O25448 (Helicobacter pylori (strain ATCC 700392 / 26695))
Explore O25448 
Go to UniProtKB:  O25448
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupO25448
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.70 Å
  • R-Value Free: 0.284 
  • R-Value Work: 0.238 
  • R-Value Observed: 0.240 
  • Space Group: I 41 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 92.469α = 90
b = 92.469β = 90
c = 144.292γ = 90
Software Package:
Software NamePurpose
CrystalCleardata collection
MOSFLMdata reduction
SCALAdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2010-06-30
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2014-02-19
    Changes: Database references
  • Version 1.3: 2023-11-01
    Changes: Data collection, Database references, Refinement description