title: Transcription in vitro of bacteriophage lambda 4S RNA: studies on termination and rho protein.
abstract: When bacteriophage lambdapga18 DNA is transcribed in a purified in vitro system by E. coli RNA polymerase (nucleoside triphosphate: RNA nucleotidyl-transferase, EC 2.7.7.6), several major transcripts are synthesized. We have investigated transcriptional termination of one of these transcripts, the 4S, or "oop" RNA. Analysis by two-dimensional "fingerprinting" of T1 oligonucleotides reveals that transcription of the 4S RNA terminates at a specific site on the lambdapga18 DNA template, t-L with an efficiency of approximately 80%, i.e. 20% of transcripts are extended into larger RNAs. Addition of the E. coli protein rho to our transcription reactions has two effects: a) the efficiency of termination at the t-L site is increased to 100%; b) the number of 4S transcripts synthesized is increased by greater than 5-fold. Rho appears to stimulate 4S RNA synthesis by facilitating more rapid release of RNA polymerase from the t-L' termination site.
mesh_terms: D001665:Binding Sites; D003090:Coliphages / Q000201:enzymology; D004279:DNA, Viral / Q000378:metabolism*; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology; D009876:Operon; D012367:RNA, Viral / Q000096:biosynthesis*; D012234:Rho Factor / Q000494:pharmacology; D012260:Ribonucleases; D013045:Species Specificity; D013698:Templates, Genetic; D014157:Transcription Factors / Q000494:pharmacology; D014158:Transcription, Genetic
chemical_list: D004279:DNA, Viral; D012367:RNA, Viral; D012234:Rho Factor; D014157:Transcription Factors; D012321:DNA-Directed RNA Polymerases; D012260:Ribonucleases