title: Structure and function of the transcription elongation factor GreB bound to bacterial RNA polymerase.
abstract: 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.
authors.affiliation: The Rockefeller University, 1230 York Avenue, New York, NY 10021, USA.
authors.forename: Natacha
authors.initials: N
authors.lastname: Opalka
authors.forename: Mark
authors.initials: M
authors.lastname: Chlenov
authors.forename: Pablo
authors.initials: P
authors.lastname: Chacon
authors.forename: William J
authors.initials: WJ
authors.lastname: Rice
authors.forename: Willy
authors.initials: W
authors.lastname: Wriggers
authors.forename: Seth A
authors.initials: SA
authors.lastname: Darst
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D001665:Binding Sites; D018360:Crystallography, X-Ray; D012321:DNA-Directed RNA Polymerases / Q000737:chemistry / Q000378:metabolism*; D004722:Endoribonucleases / Q000378:metabolism; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics; D029968:Escherichia coli Proteins; D008958:Models, Molecular; D009097:Multienzyme Complexes; D011485:Protein Binding; D020836:Protein Structure, Quaternary; D014157:Transcription Factors / Q000737:chemistry / Q000378:metabolism*; D035165:Transcription Factors, General / Q000378:metabolism; D035602:Transcriptional Elongation Factors / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; C079667:GreB protein, E coli; D009097:Multienzyme Complexes; D014157:Transcription Factors; D035165:Transcription Factors, General; D035602:Transcriptional Elongation Factors; C018648:transcription factor S-II; D012321:DNA-Directed RNA Polymerases; D004722:Endoribonucleases