title: Abortive initiation by bacteriophage T3 and T7 RNA polymerases under conditions of limiting substrate.
abstract: Initiation of RNA synthesis by the phage polymerases is abortive if the concentration of pyrimidine triphosphates is limiting. Under abortive initiation conditions the polymerases repeatedly initiate transcription but produce ribooligonucleotides that terminate just prior to the first occurrence of the limiting substrate. Abortive initiation is most severe if the limiting substrate occurs within the first 8-12 nucleotides of the nascent RNA chain and is particularly evident when UMP is limiting. The formation of stable elongation complexes (as determined by gel retardation experiments) occurs after the synthesis of an RNA product 8-12 nucleotides in length.
authors.affiliation: Department of Microbiology, Rutgers Medical School, Piscataway, NJ 08854.
authors.forename: M L
authors.initials: ML
authors.lastname: Ling
authors.forename: S S
authors.initials: SS
authors.lastname: Risman
authors.forename: J F
authors.initials: JF
authors.lastname: Klement
authors.forename: N
authors.initials: N
authors.lastname: McGraw
authors.forename: W T
authors.initials: WT
authors.lastname: McAllister
mesh_terms: D001483:Base Sequence; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D007700:Kinetics; D008969:Molecular Sequence Data; D010957:Plasmids; D011401:Promoter Regions, Genetic; D011742:Pyrimidine Nucleotides / Q000378:metabolism; D013604:T-Phages / Q000201:enzymology* / Q000235:genetics; D014158:Transcription, Genetic
chemical_list: D011742:Pyrimidine Nucleotides; D012321:DNA-Directed RNA Polymerases