The HIV-1 capsid protein C-terminal domain in complex with a virus assembly inhibitor

Nat Struct Mol Biol. 2005 Aug;12(8):678-82. doi: 10.1038/nsmb967. Epub 2005 Jul 24.


Immature HIV particles bud from infected cells after assembly at the cytoplasmic side of cellular membranes. This assembly is driven by interactions between Gag polyproteins. Mature particles, each containing a characteristic conical core, are later generated by proteolytic maturation of Gag in the virion. The C-terminal domain of the HIV-1 capsid protein (C-CA) has been shown to contain oligomerization determinants essential for particle assembly. Here we report the 1.7-A-resolution crystal structure of C-CA in complex with a peptide capable of inhibiting immature- and mature-like particle assembly in vitro. The peptide inserts as an amphipathic alpha-helix into a conserved hydrophobic groove of C-CA, resulting in formation of a compact five-helix bundle with altered dimeric interactions. This structure thus reveals the details of an allosteric site in the HIV capsid protein that can be targeted for antiviral therapy.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Capsid Proteins / chemistry
  • Capsid Proteins / metabolism*
  • Gene Products, gag / genetics
  • Gene Products, gag / metabolism*
  • HIV-1 / metabolism
  • HIV-1 / physiology*
  • Models, Molecular*
  • Multiprotein Complexes / metabolism*
  • Peptides / chemistry
  • Peptides / metabolism*
  • Protein Binding
  • Protein Structure, Tertiary
  • Virus Assembly / genetics*
  • Virus Assembly / physiology
  • X-Ray Diffraction


  • Capsid Proteins
  • Gene Products, gag
  • Multiprotein Complexes
  • Peptides