Simple Rules for Efficient Assembly Predict the Layout of a Packaged Viral RNA

Eric Charles Dykeman, Nicholas Edwin Grayson, K Toropova, Reidun Twarock, N.A. Ranson, Peter G. Stockley

Research output: Contribution to journalArticlepeer-review


Single-stranded RNA (ssRNA) viruses, which include major human
pathogens, package their genomes as they assemble their capsids. We
show here that the organization of the viral genomes within the capsids
provides intriguing insights into the highly cooperative nature of the
assembly process. A recent cryo-electron microscopy structure of bacteriophage
MS2, determined with only 5-fold symmetry averaging, has revealed
the asymmetric distribution of its encapsidated genome. Here we show that
this RNA distribution is consistent with an assembly mechanism that
follows two simple rules derived from experiment: (1) the binding of the
MS2 maturation protein to the RNA constrains its conformation into a loop,
and (2) the capsid must be built in an energetically favorable way. These
results provide a new level of insight into the factors that drive efficient
assembly of ssRNA viruses in vivo.
Original languageEnglish
Pages (from-to)399-407
Number of pages9
JournalJournal of Molecular Biology
Issue number3
Publication statusPublished - 6 May 2011


  • ssRNA virus;
  • virus assembly;
  • genome organization;
  • cryo-EM;
  • Hamiltonian path;

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