RNA cleavage and chain elongation by Escherichia coli DNA-dependent RNA polymerase in a binary enzyme.RNA complex.
In the absence of DNA, Escherichia coli RNA polymerase (EC 2.7.7.6) can bind RNA to form an equimolar binary complex with the concomitant release of the sigma factor. We show now that E. coli RNA polymerase binds at a region near the 3' terminus of the RNA and that an RNA in such RNA.RNA polymerase complexes undergoes reactions previously thought to be unique to nascent RNA in ternary complexes with DNA. These include GreA/GreB-dependent cleavage of the RNA and elongation by 3'-terminal addition of NMP from NTP. Both of these reactions are inhibited by rifampicin. Hence, by several criteria, the RNA in binary complexes is bound to the polymerase in a manner quite similar to that in ternary complexes. These findings can be explained by a model for the RNA polymerase ternary complex in which the RNA is bound at the 3' terminus through two protein binding sites located up to 10 nt apart. In this model, the stability of RNA binding to the polymerase in the ternary complex is due primarily to its interaction with the protein.
Altmann
C R
CR
Department of Molecular and Cell Biology, University of California, Berkeley 94720.
Solow-Cordero
D E
DE
Chamberlin
M J
MJ
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000378:metabolism; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D004720:Endonucleases / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology; D029968:Escherichia coli Proteins; D046911:Macromolecular Substances; D008274:Magnesium / Q000378:metabolism; D008969:Molecular Sequence Data; D010445:Peptide Elongation Factors / Q000378:metabolism; D012313:RNA / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism; D035602:Transcriptional Elongation Factors
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; C079667:GreB protein, E coli; D046911:Macromolecular Substances; D010445:Peptide Elongation Factors; D016601:RNA-Binding Proteins; D014157:Transcription Factors; D035602:Transcriptional Elongation Factors; C075886:GREA protein, Rickettsia prowazekii; D012313:RNA; D012321:DNA-Directed RNA Polymerases; D004720:Endonucleases; D008274:Magnesium