Structure of the bacteriophage phi29 DNA packaging motor

Nature. 2000 Dec 7;408(6813):745-50. doi: 10.1038/35047129.


Motors generating mechanical force, powered by the hydrolysis of ATP, translocate double-stranded DNA into preformed capsids (proheads) of bacterial viruses and certain animal viruses. Here we describe the motor that packages the double-stranded DNA of the Bacillus subtilis bacteriophage phi29 into a precursor capsid. We determined the structure of the head-tail connector--the central component of the phi29 DNA packaging motor--to 3.2 A resolution by means of X-ray crystallography. We then fitted the connector into the electron densities of the prohead and of the partially packaged prohead as determined using cryo-electron microscopy and image reconstruction analysis. Our results suggest that the prohead plus dodecameric connector, prohead RNA, viral ATPase and DNA comprise a rotary motor with the head-prohead RNA-ATPase complex acting as a stator, the DNA acting as a spindle, and the connector as a ball-race. The helical nature of the DNA converts the rotary action of the connector into translation of the DNA.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adenosine Triphosphatases / chemistry
  • Bacillus Phages / chemistry*
  • Bacillus Phages / genetics
  • Bacillus Phages / metabolism
  • Capsid / chemistry
  • Capsid / metabolism
  • Cryoelectron Microscopy
  • Crystallography, X-Ray
  • DNA, Viral / chemistry*
  • DNA, Viral / metabolism
  • Models, Molecular
  • Molecular Motor Proteins / chemistry*
  • Molecular Motor Proteins / metabolism
  • Nucleic Acid Conformation
  • RNA, Viral / chemistry


  • DNA, Viral
  • Molecular Motor Proteins
  • RNA, Viral
  • Adenosine Triphosphatases

Associated data

  • PDB/1FOQ
  • PDB/1FOU