Suppression of factor-dependent transcription termination by antiterminator RNA.
Nascent transcripts of the phage HK022 put sites modify the transcription elongation complex so that it terminates less efficiently at intrinsic transcription terminators and accelerates through pause sites. We show here that the modification also suppresses termination in vivo at two factor-dependent terminators, one that depends on the bacterial Rho protein and a second that depends on the HK022-encoded Nun protein. Suppression was efficient when the termination factors were present at physiological levels, but an increase in the intracellular concentration of Nun increased termination both in the presence and absence of put. put-mediated antitermination thus shows no apparent terminator specificity, suggesting that put inhibits a step that is common to termination at the different types of terminator.
King
Rodney A
RA
Section on Microbial Genetics, Laboratory of Molecular Genetics, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892-2785, USA.
Weisberg
Robert A
RA
D025523:Bacteriophage HK022 / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000502:physiology; D012329:RNA, Bacterial / Q000235:genetics*; D012234:Rho Factor / Q000502:physiology; D013728:Terminator Regions, Genetic; D014157:Transcription Factors / Q000502:physiology*; D014158:Transcription, Genetic; D014764:Viral Proteins / Q000502:physiology*
C073501:Nun protein, Enterobacteria phage HK022; D012329:RNA, Bacterial; D012234:Rho Factor; D014157:Transcription Factors; D014764:Viral Proteins