Structure and function of the transcription elongation factor GreB bound to bacterial RNA polymerase

Cell. 2003 Aug 8;114(3):335-45. doi: 10.1016/s0092-8674(03)00600-7.


Bacterial GreA and GreB promote transcription elongation by stimulating an endogenous, endonucleolytic transcript cleavage activity of the RNA polymerase. The structure of Escherichia coli core RNA polymerase bound to GreB was determined by cryo-electron microscopy and image processing of helical crystals to a nominal resolution of 15 A, allowing fitting of high-resolution RNA polymerase and GreB structures. In the resulting model, the GreB N-terminal coiled-coil domain extends 45 A through a channel directly to the RNA polymerase active site. The model leads to detailed insights into the mechanism of Gre factor activity that explains a wide range of experimental observations and points to a key role for conserved acidic residues at the tip of the Gre factor coiled coil in modifying the RNA polymerase active site to catalyze the cleavage reaction. Mutational studies confirm that these positions are critical for Gre factor function.

Publication types

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

MeSH terms

  • Bacterial Proteins / chemistry
  • Bacterial Proteins / metabolism*
  • Binding Sites
  • Crystallography, X-Ray
  • DNA-Directed RNA Polymerases / chemistry
  • DNA-Directed RNA Polymerases / metabolism*
  • Endoribonucleases / metabolism
  • Escherichia coli / enzymology
  • Escherichia coli / genetics
  • Escherichia coli Proteins*
  • Models, Molecular
  • Multienzyme Complexes
  • Protein Binding
  • Protein Structure, Quaternary*
  • Transcription Factors / chemistry
  • Transcription Factors / metabolism*
  • Transcription Factors, General / metabolism
  • Transcriptional Elongation Factors / metabolism*


  • Bacterial Proteins
  • Escherichia coli Proteins
  • GreB protein, E coli
  • Multienzyme Complexes
  • Transcription Factors
  • Transcription Factors, General
  • Transcriptional Elongation Factors
  • transcription factor S-II
  • DNA-Directed RNA Polymerases
  • Endoribonucleases