The C-terminal domain of the alpha subunit of Escherichia coli RNA polymerase is required for efficient rho-dependent transcription termination.
We screened a collection of single alanine residue substitution mutants spanning the entire C-terminal domain of the alpha subunit (alphaCTD) of Escherichia coli RNA polymerase (RNAP) for defects in rho-dependent transcription termination at lambdatR1 in vivo and in vitro, and thereby identified a patch of amino acid residues in the alphaCTD required for efficient rho-dependent termination. NusA addition led to the stimulation of rho-dependent termination under our conditions in vitro. The termination defects of a few mutant RNAPs could be attributed to altered interactions with the NusA protein, but rho-dependent termination by most of the defective RNAPs was still stimulated normally by NusA. The NusA-enhanced transcription pausing behaviors of the mutant RNAPs did not always correlate with their rho-dependent termination phenotypes. We conclude that the alphaCTD is a target for interactions with NusA that influence both termination and pausing, but in addition it participates in rho-dependent transcription termination in a NusA-independent manner.
Kainz
M
M
Department of Bacteriology, University of Wisconsin, 1550 Linden Drive, Madison, WI, 53706, USA.
Gourse
R L
RL
D000409:Alanine; D001426:Bacterial Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D012321:DNA-Directed RNA Polymerases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics*; D029968:Escherichia coli Proteins; D008958:Models, Molecular; D009154:Mutation; D010445:Peptide Elongation Factors; D011994:Recombinant Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D012234:Rho Factor / Q000235:genetics / Q000378:metabolism*; D013329:Structure-Activity Relationship; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic; D035602:Transcriptional Elongation Factors
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D010445:Peptide Elongation Factors; D011994:Recombinant Proteins; D012234:Rho Factor; D014157:Transcription Factors; D035602:Transcriptional Elongation Factors; C068727:nusA protein, E coli; D012321:DNA-Directed RNA Polymerases; C113275:RNA polymerase alpha subunit; D000409:Alanine