Upstream Promoter Transcribed region 20.3 Promoter 八A elements are defined NA by mutations and Delete and reconnect footprinting Transcription Figure 20.3 Promoter boundaries can be determined by making deletions that progressively RNA still made deletion does not enter promote remove more material from one side. When one deletion fails to Delete and reconnect prevent RNa synthesis but the next stops transcription. the boundary of the promoter must lie between them No RNA made deletion has entered promoter 消当 Upstream boundary of pro between ends of deletionsFigure 20.3 Promoter boundaries can be determined by making deletions that progressively remove more material from one side. When one deletion fails to prevent RNA synthesis but the next stops transcription, the boundary of the promoter must lie between them. 20.3 Promoter elements are defined by mutations and footprinting