3QG6

Structural Basis for Ligand Recognition and Discrimination of a Quorum Quenching Antibody

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Free: 0.239 
  • R-Value Work: 0.184 
  • R-Value Observed: 0.186 

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This is version 1.2 of the entry. See complete history. 


Literature

Structural Basis for Ligand Recognition and Discrimination of a Quorum-quenching Antibody.

Kirchdoerfer, R.N., Garner, A.L., Flack, C.E., Mee, J.M., Horswill, A.R., Janda, K.D., Kaufmann, G.F., Wilson, I.A.

(2011) J Biol Chem 286: 17351-17358

  • DOI: 10.1074/jbc.M111.231258
  • Primary Citation of Related Structures:  
    3QG6, 3QG7

  • PubMed Abstract: 

    • In the postantibiotic era, available treatment options for severe bacterial infections caused by methicillin-resistant Staphylococcus aureus have become limited. Therefore, new and innovative approaches are needed to combat such life-threatening infections ...

    In the postantibiotic era, available treatment options for severe bacterial infections caused by methicillin-resistant Staphylococcus aureus have become limited. Therefore, new and innovative approaches are needed to combat such life-threatening infections. Virulence factor expression in S. aureus is regulated in a cell density-dependent manner using "quorum sensing," which involves generation and secretion of autoinducing peptides (AIPs) into the surrounding environment to activate a bacterial sensor kinase at a particular threshold concentration. Mouse monoclonal antibody AP4-24H11 was shown previously to blunt quorum sensing-mediated changes in gene expression in vitro and protect mice from a lethal dose of S. aureus by sequestering the AIP signal. We have elucidated the crystal structure of the AP4-24H11 Fab in complex with AIP-4 at 2.5 Å resolution to determine its mechanism of ligand recognition. A key Glu(H95) provides much of the binding specificity through formation of hydrogen bonds with each of the four amide nitrogens in the AIP-4 macrocyclic ring. Importantly, these structural data give clues as to the interactions between the cognate staphylococcal AIP receptors AgrC and the AIPs, as AP4-24H11·AIP-4 binding recapitulates features that have been proposed for AgrC-AIP recognition. Additionally, these structural insights may enable the engineering of AIP cross-reactive antibodies or quorum quenching vaccines for use in active or passive immunotherapy for prevention or treatment of S. aureus infections.

    Organizational Affiliation: 

    Department of Molecular Biology, The Scripps Research Institute, La Jolla, California 92037, USA.



Macromolecules
Find similar proteins by: 
(by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
AP4-24H11 Light ChainA, D [auth L]218Mus musculusMutation(s): 0 
Protein Feature View
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  • Reference Sequence
Find similar proteins by: 
(by identity cutoff)  |  Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
AP4-24H11 Heavy ChainB, C [auth H]213Mus musculusMutation(s): 0 
Protein Feature View
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  • Reference Sequence
  • Find similar proteins by:  Sequence   |   Structure
Entity ID: 3
MoleculeChainsSequence LengthOrganismDetailsImage
Agr autoinducing peptideE [auth C], F [auth D]8N/AMutation(s): 0 
UniProt
Find proteins for Q9F6Z3 (Staphylococcus aureus)
Explore Q9F6Z3 
Go to UniProtKB:  Q9F6Z3
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Free: 0.239 
  • R-Value Work: 0.184 
  • R-Value Observed: 0.186 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 68.36α = 90
b = 98.498β = 114.03
c = 73.67γ = 90
Software Package:
Software NamePurpose
HKL-2000data collection
PHASERphasing
REFMACrefinement
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: 2011-03-23
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2018-01-24
    Changes: Structure summary