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Determination of the fold of the core protein of hepatitis B virus by electron cryomicroscopy

Abstract

Hepatitis B virus, a major human pathogen with an estimated 300 million carriers worldwide, can lead to cirrhosis and liver cancer in cases of chronic infection. The virus consists of an inner nucleocapsid or core, surrounded by a lipid envelope containing virally encoded surface proteins. The core protein, when expressed in bacteria, assembles into core shell particles, closely resembling the native core of the virus. Here we use electron cryomicroscopy to solve the structure of the core protein to 7.4 Å resolution. Images of about 6,400 individual particles from 34 micrographs at different levels of defocus were combined, imposing icosahedral symmetry. The three-dimensional map reveals the complete fold of the polypeptide chain, which is quite unlike previously solved viral capsid proteins and is largely α-helical. The dimer clustering of subunits produces spikes on the surface of the shell, which consist of radial bundles of four long α-helices. Our model implies that the sequence corresponding to the immunodominant region of the core protein lies at the tip of the spike and also explains other properties of the core protein.

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References

  1. Pasek, M. et al. Hepatitis B virus genes and their expression in E. coli.. Nature 282, 575–579 (1979).

    Article  ADS  CAS  Google Scholar 

  2. Cohen, B. J. & Richmond, J. E. Electron microscopy of hepatitis B core antigen synthesized in E. coli. Nature 296, 677–678 (1982).

    Article  ADS  CAS  Google Scholar 

  3. Crowther, R. A. et al. Three-dimensional structure of hepatitis B virus core particles determined by electron cryomicroscopy. Cell 77, 943–950 (1994).

    Article  CAS  Google Scholar 

  4. Gallina, A. et al. A recombinant hepatitis B core antigen polypeptide with the protamine-like domain deleted self-assembles into capsid particles but fails to bind nucleic acids. J. Virol. 63, 4645–4652 (1989).

    CAS  PubMed  PubMed Central  Google Scholar 

  5. Zlotnick, A. et al. Dimorphism of hepatitis B virus capsids is strongly influenced by the C-terminus of the capsid protein. Biochemistry 35, 7412–7421 (1996).

    Article  CAS  Google Scholar 

  6. Zheng, J., Schödel, E. & Peterson, D. L. The structure of hepadnaviral core antigens. J. Biol. Chem. 267, 9422–9429 (1992).

    CAS  PubMed  Google Scholar 

  7. Wingfield, P. T., Stahl, S. J., Williams, R. W. & Steven, A. C. Hepatitis core antigen produced in Escherichia coli: subunit composition, conformational analysis, and in vitro capsid assembly. Biochemistry 34, 4919–4932 (1995).

    Article  CAS  Google Scholar 

  8. Jones, T. A., Zou, J.-Y., Cowan, S. W. & Kjeldgaard, M. Improved methods for building protein models in electron density maps and the location of errors in these models. Acta Crystallogr. A 47, 110–119 (1991).

    Article  Google Scholar 

  9. Salfeld, J., Pfaff, E., Noah, M. & Schaller, H. Antigenic determinants and functional domains in core antigen and e antigen from hepatitis B virus. J. Virol. 63, 798–808 (1989).

    CAS  PubMed  PubMed Central  Google Scholar 

  10. Brown, A. L. et al. Foreign epitopes in immunodominant regions of hepatitis B core particles are highly immunogenic and conformationally restricted. Vaccine 9, 595–601 (1991).

    Article  CAS  Google Scholar 

  11. Schödel, F. et al. The position of heterologous epitopes inserted in hepatitis B virus core particles determines their immunogenicity. J. Virol. 66, 106–114 (1992).

    PubMed  PubMed Central  Google Scholar 

  12. Borisova, G. et al. Hybrid hepatitis B virus nucleocapsid bearing an immunodominant region from hepatitis B virus surface antigen. J. Virol. 67, 3696–3701 (1993).

    CAS  PubMed  PubMed Central  Google Scholar 

  13. Pushko, P. et al. Identification of hepatitis B virus core protein regions exposed or internalized at the surface of HBcAg particles by scanning with monoclonal antibodies. Virology 202, 912–920 (1994).

    Article  CAS  Google Scholar 

  14. Kenney, J. M., Bonsdorff, C.-H.v., Nassal, M. & Fuller, S. D. Evolutionary conservation in the hepatitis B virus core structure: comparison of human and duck cores. Structure 3, 1009–1019 (1995).

    Article  CAS  Google Scholar 

  15. Chothia, C. & Finkelstein, A. V. The classification and origins of protein folding patterns. Annu. Rev. Biochem. 59, 1007–1039 (1990).

    Article  CAS  Google Scholar 

  16. Nassal, M., Reiger, A. & Steinau, O. Topological analysis of the hepatitis B virus core particle by cysteine-cysteine cross-linking. J. Mol. Biol. 225, 1013–1025 (1992).

    Article  CAS  Google Scholar 

  17. Takahashi, K. et al. Immunochemical structure of hepatitis B e antigen in the serum. J. Immunol. 130, 2903–2907 (1983).

    CAS  PubMed  Google Scholar 

  18. Takahashi, K. et al. Molecular heterogeneity of e antigen polypeptides in sera from carriers of hepatitis B virus. J. Immunol. 147, 3156–3160 (1991).

    CAS  PubMed  Google Scholar 

  19. Wasenauer, G., Köck, J. & Schlicht, H.-J. Relevance of cysteine residues for biosynthesis and antigenicity of human hepatitis B virus e protein. J. Virol. 67, 1315–1321 (1993).

    CAS  PubMed  PubMed Central  Google Scholar 

  20. Nassal, M. & Reiger, A. An intramolecular disulfide bridge between Cys-7 and Cys61 determines the structure of the secretory core gene product (e antigen) of hepatitis B virus. J. Virol. 67, 4307–4315 (1993).

    CAS  PubMed  PubMed Central  Google Scholar 

  21. Birnbaum, F. & Nassal, M. Hepatitis B virus nucleocapsid assembly: primary structure requirements in the core protein. J. Virol. 64, 3319–3330 (1990).

    CAS  PubMed  PubMed Central  Google Scholar 

  22. Khudayakov, U. E. et al. The effect of the structure of the terminal regions of the hepatitis B virus gene C polypeptide on the formation of core antigen (HBcAg) particles. Biomed. Sci. 2, 257–265 (1991).

    Google Scholar 

  23. Bichko, V., Pushko, P., Dreilina, D., Pumpen, P. & Gren, E. Subtype ayw variant of hepatitis B virus: DNA primary structure analysis. FEBS Lett. 185, 208–212 (1985).

    Article  CAS  Google Scholar 

  24. Dubochet, J. et al. Cryo-electron microscopy of vitrified specimens. Quart. Rev. Biophys. 21, 129–228 (1988).

    Article  CAS  Google Scholar 

  25. Bellare, J. R., Davis, H. T., Scriven, L. E. & Talmon, Y. Controlled environment vitrification system: an improved sample preparation technique. J. Electron Microsc. Tech. 10, 87–111 (1988).

    Article  CAS  Google Scholar 

  26. Crowther, R. A., Henderson, R. & Smith, J. M. MRC image processing programs. J. Struct. Biol. 116, 9–16 (1996).

    Article  CAS  Google Scholar 

  27. Crowther, R. A. Procedures for three-dimensional reconstruction of spherical viruses by Fourier synthesis from electron micrographs. Phil. Trans. R. Soc. (Lond.) B 261, 221–230 (1971).

    Article  ADS  CAS  Google Scholar 

  28. Böttcher, B. & Crowther, R. A. Difference imaging reveals ordered regions of RNA in turnip yellow mosaic virus. Structure 4, 387–394 (1996).

    Article  Google Scholar 

  29. Heel, M. v. Similarity measures between images. Ultramicroscopy 21, 95–100 (1987).

    Article  Google Scholar 

  30. Vigers, G. P. A. Clathrin Assemblies in Vitreous Ice. Thesis, Univ. Cambridge (1986).

    Google Scholar 

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Böttcher, B., Wynne, S. & Crowther, R. Determination of the fold of the core protein of hepatitis B virus by electron cryomicroscopy. Nature 386, 88–91 (1997). https://doi.org/10.1038/386088a0

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