Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Article
  • Published:

The stoichiometry of Gag protein in HIV-1

Abstract

The major structural components of HIV-1 are encoded as a single polyprotein, Gag, which is sufficient for virus particle assembly. Initially, Gag forms an approximately spherical shell underlying the membrane of the immature particle. After proteolytic maturation of Gag, the capsid (CA) domain of Gag reforms into a conical shell enclosing the RNA genome. This mature shell contains 1,000–1,500 CA proteins assembled into a hexameric lattice with a spacing of 10 nm. By contrast, little is known about the structure of the immature virus. We used cryo-EM and scanning transmission EM to determine that an average (145 nm diameter) complete immature HIV particle contains 5,000 structural (Gag) proteins, more than twice the number from previous estimates. In the immature virus, Gag forms a hexameric lattice with a spacing of 8.0 nm. Thus, less than half of the CA proteins form the mature core.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Cryo-electron micrographs and schematic representations of HIV-1 particles and HIV-1 Gag protein.
Figure 2: Image processing of cryo-electron micrographs of viral particles.
Figure 3: STEM of in vitro–assembled HIV-1 Gag protein.

Similar content being viewed by others

References

  1. Wilk, T. et al. Organization of immature human immunodeficiency virus type 1. J. Virol. 75, 759–771 (2001).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  2. Li, S., Hill, C.P., Sundquist, W.I. & Finch, J.T. Image reconstructions of helical assemblies of the HIV-1 CA protein. Nature 407, 409–413 (2000).

    Article  CAS  PubMed  Google Scholar 

  3. Ganser, B.K., Li, S., Klishko, V.Y., Finch, J.T. & Sundquist, W.I. Assembly and analysis of conical models for the HIV-1 core. Science 283, 80–83 (1999).

    Article  CAS  PubMed  Google Scholar 

  4. Briggs, J.A.G., Wilk, T., Welker, R., Krausslich, H.G. & Fuller, S.D. Structural organization of authentic, mature HIV-1 virions and cores. EMBO J. 22, 1707–1715 (2003).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  5. Mayo, K. et al. Retrovirus capsid protein assembly arrangements. J. Mol Biol. 325, 225–237 (2003).

    Article  CAS  PubMed  Google Scholar 

  6. Nermut, M.V. et al. Further evidence for hexagonal organization of HIV gag protein in prebudding assemblies and immature virus like particles. J. Struct. Biol. 123, 143–149 (1998).

    Article  CAS  PubMed  Google Scholar 

  7. Cimarelli, A. & Darlix, J.L. Assembling the human immunodeficiency virus type 1. Cell Mol. Life Sci. 59, 1166–1184 (2002).

    Article  CAS  PubMed  Google Scholar 

  8. Frankel, A.D. & Young, J.A. HIV-1: fifteen proteins and an RNA. Annu. Rev. Biochem. 67, 1–25 (1998).

    Article  CAS  PubMed  Google Scholar 

  9. Wilk, T. & Fuller, S.D. Towards the structure of the human immunodeficiency virus: divide and conquer. Curr. Opin. Struct. Biol. 9, 231–243 (1999).

    Article  CAS  PubMed  Google Scholar 

  10. Turner, B.G. & Summers, M.F. Structural biology of HIV. J. Mol. Biol. 285, 1–32 (1999).

    Article  CAS  PubMed  Google Scholar 

  11. Piatak, M. et al. High-levels of HIV-1 in plasma during all stages of infection determined by competitive PCR. Science 259, 1749–1754 (1993).

    Article  CAS  PubMed  Google Scholar 

  12. Layne, S.P. et al. Factors underlying spontaneous inactivation and susceptibility to neutralization of human-immunodeficiency-virus. Virology 189, 695–714 (1992).

    Article  CAS  PubMed  Google Scholar 

  13. Zhu, P. et al. Electron tomography analysis of envelope glycoprotein trimers on HIV and simian immunodeficiency virus virions. Proc. Natl. Acad. Sci. USA 100, 15812–15817 (2003).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  14. Vogt, V.M. & Simon, M.N. Mass determination of rous sarcoma virus virions by scanning transmission electron microscopy. J. Virol. 73, 7050–7055 (1999).

    CAS  PubMed  PubMed Central  Google Scholar 

  15. Wilk, T., Gowen, B.E. & Fuller, S.D. Actin associates with the nucleocapsid domain of the Gag polyprotein in the human immunodeficiency virus (HIV-1). J. Virol. 73, 1931–1940 (1999).

    CAS  PubMed  PubMed Central  Google Scholar 

  16. Accola, M.A., Strack, B. & Gottlinger, H.G. Efficient particle production by minimal gag constructs which retain the carboxy-terminal domain of human immunodeficiency virus type 1 capsid-p2 and a late assembly domain. J. Virol. 74, 5395–5402 (2000).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  17. Johnson, M.C., Scobie, H.M., Ma, Y.M. & Vogt, V.M. Nucleic acid-independent retrovirus assembly can be driven by dimerization. J. Virol. 76, 11177–11185 (2002).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  18. Zhang, Y.Q., Qian, H.Y., Love, Z. & Barklis, E. Analysis of the assembly function of the human immunodeficiency virus type 1 gag protein nucleocapsid domain. J. Virol. 72, 1782–1789 (1998).

    CAS  PubMed  PubMed Central  Google Scholar 

  19. Gamble, T.R. et al. Structure of the carboxyl-terminal dimerization domain of the HIV-1 capsid protein. Science 278, 849–853 (1997).

    Article  CAS  PubMed  Google Scholar 

  20. del Alamo, M., Neira, J.L. & Mateu, M.G. Thermodynamic dissection of a low affinity protein-protein interface involved in human immunodeficiency virus assembly. J. Biol. Chem. 278, 27923–27929 (2003).

    Article  CAS  PubMed  Google Scholar 

  21. Gross, I., Hohenberg, H., Huckhagel, C. & Krausslich, H.G. N-terminal extension of human immunodeficiency virus capsid protein converts the in vitro assembly phenotype from tubular to spherical particles. J. Virol. 72, 4798–4810 (1998).

    CAS  PubMed  PubMed Central  Google Scholar 

  22. Gross, I. et al. A conformational switch controlling HIV-1 morphogenesis. EMBO J. 19, 103–113 (2000).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  23. Campbell, S. & Rein, A. In vitro assembly properties of human immunodeficiency virus type 1 Gag protein lacking the p6 domain. J. Virol. 73, 2270–2279 (1999).

    CAS  PubMed  PubMed Central  Google Scholar 

  24. Wall, J.S., Hainfeld, J.F. & Simon, M.N. Scanning transmission electron microscopy of nuclear structures. Methods Cell Biol. 53, 139–164 (1998).

    Article  CAS  PubMed  Google Scholar 

  25. Muller, B., Tessmer, U., Schubert, U. & Krausslich, H.G. Human immunodeficiency virus type 1 Vpr protein is incorporated into the virion in significantly smaller amounts than Gag and is phosphorylated in infected cells. J. Virol. 74, 9727–9731 (2000).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  26. Franke, E.K., Yuan, H.E.H. & Luban, J. Specific incorporation of cyclophilin-A into HIV-1 virions. Nature 372, 359–362 (1994).

    Article  CAS  PubMed  Google Scholar 

  27. Freed, E.O. HIV-1 Gag protein: diverse functions in the virus life cycle. Virology. 251, 1–15 (1998).

    Article  CAS  PubMed  Google Scholar 

  28. Welker, R., Hohenberg, H., Tessmer, U., Huckhagel, C. & Krausslich, H.G. Biochemical and structural analysis of isolated mature cores of human immunodeficiency virus type 1. J. Virol. 74, 1168–1177 (2000).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  29. Forshey, B.M. & Aiken, C. Disassembly of human immunodeficiency virus type 1 cores in vitro reveals association of Nef with the subviral ribonucleoprotein complex. J. Virol. 77, 4409–4414 (2003).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  30. Lanman, J. et al. Key interactions in HIV-1 maturation identified by mass spectrometry based H/D exchange. Nat. Struct. Mol. Biol. 11, 676–677 (2004).

    Article  CAS  PubMed  Google Scholar 

  31. Fuller, S.D., Wilk, T., Gowen, B.E., Krausslich, H.G. & Vogt, V.M. Cryo-electron microscopy reveals ordered domains in the immature HIV-1 particle. Curr. Biol. 7, 729–738 (1997).

    Article  CAS  PubMed  Google Scholar 

  32. Press, W.H., Flannery, B.P., Teukolsky, S.A. & Vetterling, W.T. Numerical Recipes in Fortran 77 (Cambridge Univ. Press, Cambridge, UK, 1992).

    Google Scholar 

  33. Yu, F. et al. Characterization of Rous sarcoma virus Gag particles assembled in vitro. J. Virol. 75, 2753–2764 (2001).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

Download references

Acknowledgements

We thank D.I. Stuart, E.Y. Jones, R. Matadeen, R.L. Kingston and R.J. Hurrelbrink for critical readings of the manuscript, D.I. Stuart and E.Y. Jones for discussions of diffraction analysis and K.V. Fernando for help with programming. The BNL STEM is a US National Institutes of Health (NIH) supported resource center, NIH P41–RR01777, with additional support provided by the US Department of Energy, Office of Biological and Environmental Research. This work was supported by a Wellcome Trust Programme Grant to S.D.F., a US Public Health Service grant to V.M.V. and a Deutsche Forschungsgemeinschaft grant to H.-G.K. J.A.G.B. holds a Wellcome Trust structural biology studentship. S.D.F. is a Wellcome Trust principal research fellow.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Marc C Johnson.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Briggs, J., Simon, M., Gross, I. et al. The stoichiometry of Gag protein in HIV-1. Nat Struct Mol Biol 11, 672–675 (2004). https://doi.org/10.1038/nsmb785

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nsmb785

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing