Transcription against an applied force Academic Article uri icon


MeSH Major

  • DNA-Directed RNA Polymerases
  • Escherichia coli
  • Transcription, Genetic


  • The force produced by a single molecule of Escherichia coli RNA polymerase during transcription was measured optically. Polymerase immobilized on a surface was used to transcribe a DNA template attached to a polystyrene bead 0.5 micrometer in diameter. The bead position was measured by interferometry while a force opposing translocation of the polymerase along the DNA was applied with an optical trap. At saturating nucleoside triphosphate concentrations, polymerase molecules stalled reversibly at a mean applied force estimated to be 14 piconewtons. This force is substantially larger than those measured for the cytoskeletal motors kinesin and myosin and exceeds mechanical loads that are estimated to oppose transcriptional elongation in vivo. The data are consistent with efficient conversion of the free energy liberated by RNA synthesis into mechanical work.

publication date

  • December 8, 1995



  • Academic Article



  • eng

PubMed ID

  • 7502073

Additional Document Info

start page

  • 1653

end page

  • 7


  • 270


  • 5242