Ribosomal RNA transcription: proteins and DNA sequences involved in preinitiation complex formation.
An in vitro transcription system consisting of partially purified transcription initiation factor(s) and purified RNA polymerase I from Acanthamoeba castellanii was used to study the mechanism of faithful initiation of ribosomal RNA transcription. Formation of a preinitiation complex between one or several auxiliary transcription proteins and the DNA template in the absence of RNA polymerase I was demonstrated. A series of 3'- and 5'-deletion mutants of the template was used in prebinding competition experiments and provided evidence for three distinct functional regions of the promoter: core motif A interacts with the transcription initiation factor(s) and is required for faithful transcription; the start motif is required for transcription, but it can be deleted without affecting the binding of transcription initiation factor(s); and motif B stabilizes preinitiation complex formation (in addition to core motif A), but it is dispensable for faithful initiation of transcription.
D000656:Amoeba / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D001667:Binding, Competitive; D002872:Chromosome Deletion; D004247:DNA / Q000378:metabolism; D009876:Operon; D011506:Proteins / Q000378:metabolism; D012335:RNA, Ribosomal / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic
D011506:Proteins; D012335:RNA, Ribosomal; D014157:Transcription Factors; D004247:DNA