Coupling between transcription termination and RNA polymerase inchworming

Cell. 1995 May 5;81(3):351-7. doi: 10.1016/0092-8674(95)90388-7.


Advancement of RNA polymerase of E. coli occurs in alternating laps of monotonic and inchworm-like movement. Cycles of inchworming are encoded in DNA and involve straining and relaxation of the ternary complex accompanied by characteristic leaping of DNA and RNA footprints. We demonstrate that the oligo(T) tract that constitutes a normal part of transcription terminators acts as an inchworming signal so that the leap coincides with the termination event. Prevention of leaping with a roadblock of cleavage-defective EcoRI protein results in suppression of RNA chain release at a termination site. The results indicate that straining and relaxation of RNA polymerase are steps in the termination mechanism.

Publication types

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

MeSH terms

  • Base Sequence
  • Cell-Free System
  • DNA-Directed RNA Polymerases / metabolism*
  • Enzymes, Immobilized / metabolism
  • Escherichia coli / enzymology
  • Escherichia coli Proteins*
  • Models, Genetic
  • Molecular Sequence Data
  • Peptide Elongation Factors / metabolism
  • Protein Conformation
  • Terminator Regions, Genetic*
  • Transcription Factors / metabolism
  • Transcription, Genetic*
  • Transcriptional Elongation Factors


  • Enzymes, Immobilized
  • Escherichia coli Proteins
  • GreB protein, E coli
  • Peptide Elongation Factors
  • Transcription Factors
  • Transcriptional Elongation Factors
  • DNA-Directed RNA Polymerases