pT181 plasmid replication is regulated by a countertranscript-driven transcriptional attenuator.
pT181 is the prototype of a family of staphylococcal plasmids that regulate their replication by means of antisense RNAs (countertranscripts) that block expression of the plasmid-coded initiator protein. In this paper, we show that the pT181 countertranscripts induce premature termination (attenuation) of the initiator mRNA by promoting the formation of a termination-causing hairpin just 5' to the initiator start codon. In the absence of the countertranscripts, an upstream sequence, the preemptor, pairs with the proximal arm of the terminator hairpin, preventing termination and permitting transcription of the initiator gene. This system thus differs from the classical attenuators in that attenuation is driven by antisense RNAs rather than by tRNA-induced stalling of ribosomes.
Novick
R P
RP
Public Health Research Institute, New York, New York 10016.
Iordanescu
S
S
Projan
S J
SJ
Kornblum
J
J
Edelman
I
I
D001426:Bacterial Proteins / Q000235:genetics; D001483:Base Sequence; D004261:DNA Replication; D004268:DNA-Binding Proteins / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D010957:Plasmids; D012313:RNA / Q000235:genetics; D016372:RNA, Antisense; D012333:RNA, Messenger / Q000037:antagonists & inhibitors / Q000235:genetics; D015183:Restriction Mapping; D013211:Staphylococcus aureus / Q000235:genetics*; D014158:Transcription, Genetic
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D016372:RNA, Antisense; D012333:RNA, Messenger; C043650:RepC protein, Staphylococcus aureus; D012313:RNA