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Molecular tectonic model of virus structural transitions: the putative cell entry states of poliovirus

D M Belnap1, D J Filman, B L Trus

  • 1Laboratory of Structural Biology, National Institute of Arthritis, Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA.

Journal of Virology
|January 11, 2000
PubMed

Insights

Poliovirus entry involves significant structural changes, revealing gaps in the capsid that allow viral proteins to emerge. These structural shifts are crucial for viral RNA entry into host cells.

Area of Science:

  • Structural biology
  • Virology
  • Molecular biology

Background:

  • Poliovirus entry into host cells is a complex process involving conformational changes.
  • Externalization of viral proteins VP4 and VP1 N-terminus is critical for cell entry.

Purpose of the Study:

  • To determine the structures of poliovirus native virions and cell entry intermediates.
  • To elucidate the structural basis of poliovirus cell entry mechanisms.

Main Methods:

  • Cryo-electron microscopy was used to determine structures at approximately 22-Å resolution.
  • Pseudoatomic models were constructed by fitting known protein structures into the reconstructions.
  • Analysis of domain movements within the viral capsid.

Main Results:

  • Structures of native virions, 135S, and 80S particles were resolved.
  • 135S and 80S particles showed a 4% increase in size compared to the virion.
  • Domain movements up to 9 Å were observed, creating inter-subunit gaps.

Conclusions:

  • The observed structural changes and gaps provide plausible mechanisms for VP4 and VP1 N-terminus externalization.
  • These findings support models of viral RNA translocation through a transmembrane pore.
  • Structural insights advance understanding of poliovirus infection and potential therapeutic targets.

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