Structural changes of tailless bacteriophage Φx174 during penetration of bacterial cell walls

Yingyuan Sun, Aaron P. Roznowski, Joshua M. Tokuda, Thomas Klose, Alexander Mauney, Lois Pollack, Bentley A Fane, Michael G. Rossmann

Research output: Contribution to journalArticle

7 Scopus citations


Unlike tailed bacteriophages, which use a preformed tail for transporting their genomes into a host bacterium, the ssDNA bacteriophage ΦX174 is tailless. Using cryo-electron microscopy and time-resolved small-angle X-ray scattering, we show that lipopolysaccharides (LPS) form bilayers that interact with ΦX174 at an icosahedral fivefold vertex and induce single-stranded (ss) DNA genome ejection. The structures of ΦX174 complexed with LPS have been determined for the pre- and post-ssDNA ejection states. The ejection is initiated by the loss of the G protein spike that encounters the LPS, followed by conformational changes of two polypeptide loops on the major capsid F proteins. One of these loops mediates viral attachment, and the other participates in making the fivefold channel at the vertex contacting the LPS.

Original languageEnglish (US)
Pages (from-to)13708-13713
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number52
Publication statusPublished - Dec 26 2017



  • Bacteriophage
  • Cryo-EM
  • DNA ejection
  • Lipopolysaccharide
  • ΦX174

ASJC Scopus subject areas

  • General

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