A consensus motif common to all Rho-dependent prokaryotic transcription terminators.
We have characterized at the molecular level several polar mutations in four different cistrons of the his operon of S. typhimurium. An analysis of the his-specific transcripts produced in vivo in the mutant strains, together with in vitro transcription assays, led to the identification of several cryptic Rho-dependent transcription termination elements within the his operon that are activated by the uncoupling of transcription and translation. Common features of these elements were sought and found with a computer program. We have identified a consensus motif, consisting of a cytosine-rich and guanosine-poor region, that is located upstream of the heterogeneous 3' endpoints of the prematurely terminated in vivo transcripts and that is present in all the Rho-dependent transcription terminators described thus far.
Alifano
P
P
Dipartimento di Biologia e Patologia Cellulare e Molecolare, Università di Napoli, Italy.
Rivellini
F
F
Limauro
D
D
Bruni
C B
CB
Carlomagno
M S
MS
D001483:Base Sequence; D015152:Blotting, Northern; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000235:genetics; D006639:Histidine; D008969:Molecular Sequence Data; D009154:Mutation; D009876:Operon; D012329:RNA, Bacterial / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D012045:Regulatory Sequences, Nucleic Acid; D015183:Restriction Mapping; D012234:Rho Factor / Q000502:physiology*; D012486:Salmonella typhimurium / Q000235:genetics*; D013728:Terminator Regions, Genetic; D014158:Transcription, Genetic
D004269:DNA, Bacterial; D012329:RNA, Bacterial; D012333:RNA, Messenger; D012234:Rho Factor; D006639:Histidine