4GXV

Crystal structure of anti-influenza virus antibody 1F1


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.449 Å
  • R-Value Free: 0.207 
  • R-Value Work: 0.181 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Influenza Human Monoclonal Antibody 1F1 Interacts with Three Major Antigenic Sites and Residues Mediating Human Receptor Specificity in H1N1 Viruses.

Tsibane, T.Ekiert, D.C.Krause, J.C.Martinez, O.Crowe, J.E.Wilson, I.A.Basler, C.F.

(2012) Plos Pathog. 8: e1003067-e1003067

  • DOI: 10.1371/journal.ppat.1003067
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Most monoclonal antibodies (mAbs) to the influenza A virus hemagglutinin (HA) head domain exhibit very limited breadth of inhibitory activity due to antigenic drift in field strains. However, mAb 1F1, isolated from a 1918 influenza pandemic survivor, ...

    Most monoclonal antibodies (mAbs) to the influenza A virus hemagglutinin (HA) head domain exhibit very limited breadth of inhibitory activity due to antigenic drift in field strains. However, mAb 1F1, isolated from a 1918 influenza pandemic survivor, inhibits select human H1 viruses (1918, 1943, 1947, and 1977 isolates). The crystal structure of 1F1 in complex with the 1918 HA shows that 1F1 contacts residues that are classically defined as belonging to three distinct antigenic sites, Sa, Sb and Ca(2). The 1F1 heavy chain also reaches into the receptor binding site (RBS) and interacts with residues that contact sialoglycan receptors and determine HA receptor specificity. The 1F1 epitope is remarkably similar to the previously described murine HC63 H3 epitope, despite significant sequence differences between H1 and H3 HAs. Both antibodies potently inhibit receptor binding, but only HC63 can block the pH-induced conformational changes in HA that drive membrane fusion. Contacts within the RBS suggested that 1F1 may be sensitive to changes that alter HA receptor binding activity. Affinity assays confirmed that sequence changes that switch the HA to avian receptor specificity affect binding of 1F1 and a mAb possessing a closely related heavy chain, 1I20. To characterize 1F1 cross-reactivity, additional escape mutant selection and site-directed mutagenesis were performed. Residues 190 and 227 in the 1F1 epitope were found to be critical for 1F1 reactivity towards 1918, 1943 and 1977 HAs, as well as for 1I20 reactivity towards the 1918 HA. Therefore, 1F1 heavy-chain interactions with conserved RBS residues likely contribute to its ability to inhibit divergent HAs.


    Organizational Affiliation

    Department of Microbiology, Mount Sinai School of Medicine, New York City, New York, United States of America.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Antibody 1F1, heavy chain
H, I
231N/A
Protein Feature View is not available: No corresponding UniProt sequence found.
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Antibody 1F1, light chain
L, M
217N/A
Protein Feature View is not available: No corresponding UniProt sequence found.
Small Molecules
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
PCA
Query on PCA
H, I, L, M
L-PEPTIDE LINKINGC5 H7 N O3GLU
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.449 Å
  • R-Value Free: 0.207 
  • R-Value Work: 0.181 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 51.789α = 90.00
b = 99.461β = 90.00
c = 175.095γ = 90.00
Software Package:
Software NamePurpose
HKL-2000data scaling
Blu-Icedata collection
PHENIXrefinement
HKL-2000data reduction
PHASERphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2012-12-19
    Type: Initial release
  • Version 1.1: 2012-12-26
    Type: Database references