2KNS

Helical Hairpin Structure of Pardaxin in Lipopolysaccharide Micelles: Studied by NMR Spectroscopy


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 200 
  • Conformers Submitted: 20 
  • Selection Criteria: target function 

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This is version 1.1 of the entry. See complete history


Literature

NMR structure of pardaxin, a pore-forming antimicrobial peptide, in lipopolysaccharide Micelles: Mechanism of outer membrane permeabilization

Bhunia, A.Domadia, P.N.Torres, J.Hallock, K.J.Ramamoorthy, A.Bhattacharjya, S.

(2010) J Biol Chem 285: 3883-3895

  • DOI: 10.1074/jbc.M109.065672
  • Primary Citation of Related Structures:  
    2KNS

  • PubMed Abstract: 
  • Lipopolysaccharide (LPS), the major constituent of the outer membrane of Gram-negative bacteria, is an important element against permeability of bactericidal agents, including antimicrobial peptides. However, structural determinants of antimicrobial peptides for LPS recognition are not clearly understood ...

    Lipopolysaccharide (LPS), the major constituent of the outer membrane of Gram-negative bacteria, is an important element against permeability of bactericidal agents, including antimicrobial peptides. However, structural determinants of antimicrobial peptides for LPS recognition are not clearly understood. Pardaxins (Pa1, Pa2, Pa3, and Pa4) are a group of pore-forming bactericidal peptides found in the mucous glands of sole fishes. Despite having a low net positive charge, pardaxins contain a broad spectrum of antibacterial activities. To elucidate the structural basis of LPS interactions of pardaxins, herein, we report the first three-dimensional structure of Pa4 bound to LPS micelles. The binding kinetics of Pa4 with LPS is estimated using [(15)N-Leu-19] relaxation dispersion NMR experiments. LPS/Pa4 interactions are further characterized by a number of biophysical methods, including isothermal titration calorimetry, (31)P NMR, saturation transfer difference NMR, dynamic light scattering, and IR spectroscopy. In the LPS-Pa4 complex, Pa4 adopts a unique helix-turn-helix conformation resembling a "horseshoe." Interestingly, the LPS-bound structure of Pa4 shows striking differences with the structures determined in lipid micelles or organic solvents. Saturation transfer difference NMR identifies residues of Pa4 that are intimately associated with LPS micelles. Collectively, our results provide mechanistic insights into the outer membrane permeabilization by pardaxin.


    Organizational Affiliation

    Division of Structural and Computational Biology, Nanyang Technological University, School of Biological Sciences, Singapore.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Pardaxin P-4A33Pardachirus marmoratusMutation(s): 0 
Membrane Entity: Yes 
UniProt
Find proteins for P81861 (Pardachirus marmoratus)
Explore P81861 
Go to UniProtKB:  P81861
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 200 
  • Conformers Submitted: 20 
  • Selection Criteria: target function 
  • OLDERADO: 2KNS Olderado

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2009-12-15
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance