To Build a Virus on a Nucleic Acid Substrate

Biophys J. 2013 Apr 2;104(7):1595-604. doi: 10.1016/j.bpj.2013.02.005.


Many viruses package their genomes concomitant with assembly. Here, we show that this reaction can be described by three coefficients: association of capsid protein (CP) to nucleic acid (NA), KNA; CP-CP interaction, ω; and α, proportional to the work required to package NA. The value of α can vary as NA is packaged. A phase diagram of average lnα versus lnω identifies conditions where assembly is likely to fail or succeed. NA morphology can favor (lnα > 0) or impede (lnα < 0) assembly. As lnω becomes larger, capsids become more stable and assembly becomes more cooperative. Where (lnα + lnω) < 0, the CP is unable to contain the NA, so that assembly results in aberrant particles. This phase diagram is consistent with quantitative studies of cowpea chlorotic mottle virus, hepatitis B virus, and simian virus 40 assembling on ssRNA and dsDNA substrates. Thus, the formalism we develop is suitable for describing and predicting behavior of experimental studies of CP assembly on NA.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Capsid Proteins / metabolism
  • DNA Packaging
  • DNA, Viral / chemistry
  • DNA, Viral / genetics
  • DNA, Viral / metabolism*
  • Models, Molecular
  • Molecular Conformation
  • RNA, Viral / chemistry
  • RNA, Viral / genetics
  • RNA, Viral / metabolism*
  • Virion / genetics
  • Virion / metabolism
  • Viruses / genetics*
  • Viruses / metabolism*


  • Capsid Proteins
  • DNA, Viral
  • RNA, Viral