The bacteriophage DNA packaging motor

Annu Rev Genet. 2008;42:647-81. doi: 10.1146/annurev.genet.42.110807.091545.


An ATP-powered DNA translocation machine encapsidates the viral genome in the large dsDNA bacteriophages. The essential components include the empty shell, prohead, and the packaging enzyme, terminase. During translocation, terminase is docked on the prohead's portal protein. The translocation ATPase and the concatemer-cutting endonuclease reside in terminase. Remarkably, terminases, portal proteins, and shells of tailed bacteriophages and herpes viruses show conserved features. These DNA viruses may have descended from a common ancestor. Terminase's ATPase consists of a classic nucleotide binding fold, most closely resembling that of monomeric helicases. Intriguing models have been proposed for the mechanism of dsDNA translocation, invoking ATP hydrolysis-driven conformational changes of portal or terminase powering DNA motion. Single-molecule studies show that the packaging motor is fast and powerful. Recent advances permit experiments that can critically test the packaging models. The viral genome translocation mechanism is of general interest, given the parallels between terminases, helicases, and other motor proteins.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Review

MeSH terms

  • Amino Acid Sequence
  • Bacteriophages / genetics*
  • Bacteriophages / physiology*
  • DNA Packaging / genetics*
  • DNA Packaging / physiology*
  • DNA, Viral / chemistry
  • DNA, Viral / genetics
  • DNA, Viral / metabolism
  • Models, Biological
  • Models, Molecular
  • Molecular Motor Proteins / chemistry
  • Molecular Motor Proteins / genetics
  • Molecular Motor Proteins / metabolism
  • Molecular Sequence Data
  • Sequence Homology, Amino Acid
  • Viral Proteins / chemistry
  • Viral Proteins / genetics
  • Viral Proteins / metabolism
  • Virus Assembly / genetics
  • Virus Assembly / physiology


  • DNA, Viral
  • Molecular Motor Proteins
  • Viral Proteins