4NYT

L-Ficolin Complexed to Phosphocholine


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.25 Å
  • R-Value Free: 0.243 
  • R-Value Work: 0.213 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Human L-ficolin recognizes phosphocholine moieties of pneumococcal teichoic Acid

Vassal-Stermann, E.Lacroix, M.Gout, E.Laffly, E.Pedersen, C.M.Martin, L.Amoroso, A.Schmidt, R.R.Zahringer, U.Gaboriaud, C.Di Guilmi, A.M.Thielens, N.M.

(2014) J.Immunol. 193: 5699-5708

  • DOI: 10.4049/jimmunol.1400127

  • PubMed Abstract: 
  • Human L-ficolin is a soluble protein of the innate immune system able to sense pathogens through its fibrinogen (FBG) recognition domains and to trigger activation of the lectin complement pathway through associated serine proteases. L-Ficolin has be ...

    Human L-ficolin is a soluble protein of the innate immune system able to sense pathogens through its fibrinogen (FBG) recognition domains and to trigger activation of the lectin complement pathway through associated serine proteases. L-Ficolin has been previously shown to recognize pneumococcal clinical isolates, but its ligands and especially its molecular specificity remain to be identified. Using solid-phase binding assays, serum and recombinant L-ficolins were shown to interact with serotype 2 pneumococcal strain D39 and its unencapsulated R6 derivative. Incubation of both strains with serum triggered complement activation, as measured by C4b and C3b deposition, which was decreased by using ficolin-depleted serum. Recombinant L-ficolin and its FBG-like recognition domain bound to isolated pneumococcal cell wall extracts, whereas binding to cell walls depleted of teichoic acid (TA) was decreased. Both proteins were also shown to interact with two synthetic TA compounds, each comprising part structures of the complete lipoteichoic acid molecule with two PCho residues. Competition studies and direct interaction measurements by surface plasmon resonance identified PCho as a novel L-ficolin ligand. Structural analysis of complexes of the FBG domain of L-ficolin and PCho revealed that the phosphate moiety interacts with amino acids previously shown to define an acetyl binding site. Consequently, binding of L-ficolin to immobilized acetylated BSA was inhibited by PCho and synthetic TA. Binding of serum L-ficolin to immobilized synthetic TA and PCho-conjugated BSA triggered activation of the lectin complement pathway, thus further supporting the hypothesis of L-ficolin involvement in host antipneumococcal defense.


    Organizational Affiliation

    University of Grenoble Alpes, Institut de Biologie Structurale, F-38044 Grenoble, France; Centre National de la Recherche Scientifique, Institut de Biologie Structurale, F-38044 Grenoble, France; Commissariat à l'Energie Atomique et aux Energies Alternatives, Institut de Biologie Structurale, F-38044 Grenoble, France;




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Ficolin-2
C, A, B
217Homo sapiensMutation(s): 0 
Gene Names: FCN2 (FCNL)
Find proteins for Q15485 (Homo sapiens)
Go to Gene View: FCN2
Go to UniProtKB:  Q15485
Small Molecules
Ligands 7 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
PC
Query on PC

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A
PHOSPHOCHOLINE
C5 H15 N O4 P
YHHSONZFOIEMCP-UHFFFAOYSA-O
 Ligand Interaction
PO4
Query on PO4

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C
PHOSPHATE ION
O4 P
NBIIXXVUZAFLBC-UHFFFAOYSA-K
 Ligand Interaction
ACT
Query on ACT

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A, C
ACETATE ION
C2 H3 O2
QTBSBXVTEAMEQO-UHFFFAOYSA-M
 Ligand Interaction
CA
Query on CA

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A, B, C
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
MAN
Query on MAN

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C
ALPHA-D-MANNOSE
C6 H12 O6
WQZGKKKJIJFFOK-PQMKYFCFSA-N
 Ligand Interaction
FUC
Query on FUC

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C
ALPHA-L-FUCOSE
C6 H12 O5
SHZGCJCMOBCMKK-SXUWKVJYSA-N
 Ligand Interaction
NAG
Query on NAG

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A, C
N-ACETYL-D-GLUCOSAMINE
C8 H15 N O6
OVRNDRQMDRJTHS-FMDGEEDCSA-N
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
PCKd: 3700000 nM BINDINGMOAD
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.25 Å
  • R-Value Free: 0.243 
  • R-Value Work: 0.213 
  • Space Group: P 32 2 1
Unit Cell:
Length (Å)Angle (°)
a = 96.130α = 90.00
b = 96.130β = 90.00
c = 139.880γ = 120.00
Software Package:
Software NamePurpose
ADSCdata collection
REFMACrefinement
XSCALEdata scaling
PHASERphasing
XDSdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2014-10-29
    Type: Initial release
  • Version 1.1: 2014-12-24
    Type: Database references