title: Factor-independent termination of transcription in a stretch of deoxyadenosine residues in the template DNA.
abstract: The primer transcript of plasmid ColE1 extends beyond the replication origin in either of two different modes. It does or does not form a hybrid with the template DNA. When a stretch of 20 deoxyadenosine residues is inserted into the template strand downstream of the origin, more than 90% of hybridized transcripts and about 10% of unhybridized transcripts terminate at the insert. When the number of inserted residues is reduced to ten, the corresponding values are decreased considerably, while the sites of termination are almost unchanged. A palindrome immediately before the stretch increased the efficiency of termination of unhybridized transcripts. Upon termination of hybridized transcripts, RNA polymerase detaches from the template. A structure made by a hybrid or by folded RNA may affect a property of transcription, and a stretch of deoxyadenosine residues including those beyond the actual site of termination may facilitate detachment of RNA polymerase from the template DNA.
mesh_terms: D003086:Bacteriocin Plasmids; D001483:Base Sequence; D004269:DNA, Bacterial / Q000235:genetics*; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism; D003839:Deoxyadenosines; D004926:Escherichia coli / Q000235:genetics*; D005809:Genes, Regulator; D009690:Nucleic Acid Conformation; D012329:RNA, Bacterial / Q000096:biosynthesis; D013698:Templates, Genetic; D013728:Terminator Regions, Genetic; D014158:Transcription, Genetic
chemical_list: D004269:DNA, Bacterial; D003839:Deoxyadenosines; D012329:RNA, Bacterial; D012321:DNA-Directed RNA Polymerases