Promoter occlusion during ribosomal RNA transcription.
The ability of RNA polymerase I to read through a promoter-bound transcription initiation factor (TIF) was assessed using a dimeric ribosomal RNA gene promoter. Transcription from the upstream promoter is unaffected by TIF bound to the downstream promoter; RNA polymerase I is freely able to read through DNA-bound TIF. In contrast, transcription from the downstream promoter is inhibited by the passage of RNA polymerase I. Readthrough by RNA polymerase I disrupts the downstream TIF-DNA complex, and alters the TIF footprint. A general function for sequences leading to transcription termination upstream of rRNA or other promoters may be the prevention of promoter occlusion in tandem arrays of genes.
Colorado State University, Department of Biochemistry, Fort Collins 80523.
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D000048:Acanthamoeba; D000818:Animals; D004268:DNA-Binding Proteins / Q000502:physiology*; D003850:Deoxyribonuclease I; D011401:Promoter Regions, Genetic; D012318:RNA Polymerase I / Q000502:physiology*; D012335:RNA, Ribosomal / Q000235:genetics; D013698:Templates, Genetic; D013997:Time Factors; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic
D004268:DNA-Binding Proteins; D012335:RNA, Ribosomal; D014157:Transcription Factors; D012318:RNA Polymerase I; D003850:Deoxyribonuclease I