Crystal structures of human immunodeficiency virus type 1 (HIV-1) neutralizing antibody 2219 in complex with three different V3 peptides reveal a new binding mode for HIV-1 cross-reactivity

J Virol. 2006 Jun;80(12):6093-105. doi: 10.1128/JVI.00205-06.


Human monoclonal antibody 2219 is a neutralizing antibody isolated from a human immunodeficiency virus type 1-infected individual. 2219 was originally selected for binding to a V3 fusion protein and can neutralize primary isolates from subtypes B, A, and F. Thus, 2219 represents a cross-reactive, human anti-V3 antibody. Fab 2219 binds to one face of the variable V3 beta-hairpin, primarily contacting conserved residues on the N-terminal beta-strand of V3, leaving the V3 crown or tip largely accessible. Three V3/2219 complexes reveal the antibody-bound conformations for both the N- and C-terminal regions that flank the V3 crown and illustrate how twisting of the V3 loop alters the relative dispositions and pairing of the amino acids in the adjacent V3 beta-strands and how the antibody can accommodate V3 loops with different sequences.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Antigen-Antibody Complex / chemistry*
  • Cross Reactions / immunology*
  • Crystallization
  • Crystallography, X-Ray
  • Epitopes
  • HIV Antibodies / chemistry*
  • HIV Envelope Protein gp120 / chemistry*
  • HIV-1 / immunology*
  • Humans
  • Peptide Fragments / chemistry*
  • Protein Conformation
  • Protein Structure, Secondary


  • Antigen-Antibody Complex
  • Epitopes
  • HIV Antibodies
  • HIV Envelope Protein gp120
  • HIV envelope protein gp120 (305-321)
  • Peptide Fragments