A transcription antiterminator constructs a NusA-dependent shield to the emerging transcript.
The universal bacterial transcription elongation factor NusA mediates elongation activities of RNA polymerase. By itself, NusA induces transcription pausing and facilitates intrinsic termination, but NusA also is a cofactor of antiterminators that antagonize pausing and prevent termination. We show that NusA is required for lambda-related phage 82 antiterminator Q(82) to construct a stable complex in which RNA-based termination mechanisms have restricted access to the emerging transcript; this result suggests a locale for both Q(82) and NusA near the beta flap domain of RNA polymerase. Furthermore, as NusA is not required for the antipausing activity of Q(82) in vitro, we distinguish two distinct activities of antiterminators, namely antipausing and RNA occlusion, and discuss their roles in Q(82) function.
Shankar
Smita
S
Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA.
Hatoum
Asma
A
Roberts
Jeffrey W
JW
D001426:Bacterial Proteins / Q000378:metabolism*; D001483:Base Sequence; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000378:metabolism*; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009841:Oligonucleotides / Q000378:metabolism; D010445:Peptide Elongation Factors / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000235:genetics; D012329:RNA, Bacterial / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000378:metabolism*; D012234:Rho Factor / Q000378:metabolism; D016914:Ribonuclease H / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic; D035602:Transcriptional Elongation Factors
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D009841:Oligonucleotides; D010445:Peptide Elongation Factors; D012329:RNA, Bacterial; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D012234:Rho Factor; D014157:Transcription Factors; D035602:Transcriptional Elongation Factors; C064872:antiterminator proteins, Bacteria; C068727:nusA protein, E coli; C072103:transcription repair coupling factor protein, Bacteria; D012321:DNA-Directed RNA Polymerases; D016914:Ribonuclease H