The core promoter of mouse rDNA consists of two functionally distinct domains.
We have determined the sequences constituting the minimal promoter of mouse rDNA. A very small region immediately upstream of the transcription start site (from -1 to -39) is sufficient to direct correct transcription initiation. Sequences immediately downstream of the transcription start site (+1 to +11) increase the efficiency of transcription initiation. Point mutations within the core promoter have been generated and assayed for their effects on template activity and on interaction with the pol I specific transcription factor TIF-IB. The core promoter element appears to consist of two functionally different domains. The distal sequence motif from position -22 to -16 is recognized by factor TIF-IB. Mutations within this region lead to similar changes of both template activity and binding of TIF-IB. Two point mutations within the proximal sequence motif from -15 to -1 do not affect TIF-IB binding although they severely impair transcription initiation. It is suggested, that this proximal region plays a role in the assembly of functional transcription initiation complexes rather than in the primary binding of TIF-IB.
D000818:Animals; D001483:Base Sequence; D004275:DNA, Ribosomal / Q000032:analysis*; D051379:Mice; D009154:Mutation; D011401:Promoter Regions, Genetic; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic
D004275:DNA, Ribosomal; D014157:Transcription Factors