Frpo: a novel single-stranded DNA promoter for transcription and for primer RNA synthesis of DNA replication.
We describe a novel promoter for E. coli RNA polymerase that functions efficiently only in the form of single-stranded DNA. Derived from the leading region of F plasmid, single-stranded Frpo sequence directs RNA polymerase to initiate transcription at a specific site within Frpo, and this specific transcription is highly stimulated by SSB. Prior denaturation activates transcription from otherwise inactive duplex DNA containing Frpo. Since RNAs synthesized on SSB-coated single-stranded Frpo are efficiently elongated into DNA chains by DNA polymerase III holoenzyme, transcription at Frpo serves also for priming DNA replication. A mode of recognition by RNA polymerase of a unique secondary structure within Frpo is proposed, and possible roles of this novel single-stranded promoter in expression and replication during conjugal transfer of F plasmid are discussed.
Masai
H
H
Department of Molecular and Developmental Biology, Institute of Medical Science, University of Tokyo, Minato-ku, Japan.
Arai
K
K
D002874:Chromosome Mapping; D003227:Conjugation, Genetic / Q000502:physiology; D018983:DNA Footprinting; D004261:DNA Replication / Q000502:physiology*; D004269:DNA, Bacterial / Q000096:biosynthesis; D004270:DNA, Circular / Q000235:genetics; D004277:DNA, Single-Stranded / Q000235:genetics; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism; D004926:Escherichia coli / Q000737:chemistry / Q000201:enzymology / Q000235:genetics; D005144:F Factor / Q000235:genetics / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics; D009690:Nucleic Acid Conformation; D016366:Open Reading Frames / Q000502:physiology; D011401:Promoter Regions, Genetic / Q000235:genetics*; D012313:RNA / Q000737:chemistry / Q000235:genetics*; D012329:RNA, Bacterial / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis; D014158:Transcription, Genetic / Q000235:genetics*
D004269:DNA, Bacterial; D004270:DNA, Circular; D004277:DNA, Single-Stranded; C034477:RNA primers; D012329:RNA, Bacterial; D012333:RNA, Messenger; D012313:RNA; D012321:DNA-Directed RNA Polymerases